1: RETURN

Bisesa Dutt gasped, and staggered.

Music was playing.

Bisesa could barely take her eyes off the wall’s moving colors, its brightness. She had forgotten how drab and dun-colored Mir had been. But then, Mir had been another world altogether.

“Shut up.” Her voice was a dusty desert croak.

She glanced around. This was her bedroom, in her London apartment. It seemed small, cluttered. The bed was big, soft, not slept in.

“Aristotle.”

“What’s the date?”

“The date.”

“I should be in Afghanistan.”

“Mum?”

Myra was barefoot, her tummy stuck out, fist rubbing at one eye, hair tousled, a barely awake eight-year-old. She was wearing her favorite pajamas, the ones across which cartoon characters gamboled, even though they were now about two sizes too small for her. “You didn’t say you were coming home.”

Her daughter recoiled. “You smell funny.”

She forced a smile. “I guess I need a shower. Then we’ll have breakfast, and I’ll tell you all about it…”

There was an Eye over the city, a silver sphere, floating like a barrage balloon. She couldn’t tell how far away it was, or how big. But she knew it was an instrument of the Firstborn, who had transported her to Mir, another world, and brought her home.

2: THE PEAK OF ETERNAL LIGHT

Mikhail Martynov had devoted his life to the study of Earth’s star. And from the first moment he saw the sun, at the beginning of that fateful day, he knew, deep in his bones, that something was wrong.

“Good morning, Mikhail. The time on the Moon is two o’clock in the morning. Good morning, Mikhail. The time is two o’clock and fifteen seconds. Good morning…”

“Thank you, Thales.” But he was already up and moving. As always he had woken to within a minute of his personal schedule, without need of Thales’s softly spoken electronic wake-up call, a schedule he kept independently of the Houston time to which the rest of the Moon was enslaved.

Mikhail was a man of routine. And he would begin the day, as he began every day of his long solitary watches in this Space Weather Service Station, with a walk into the sunlight.

He took a quick breakfast of fruit concentrate and water. He always drank the water pure, never polluted with coffee granules or tea leaves, for it was water from the Moon, the result of billions of years of slow cometary accretion and now mined and processed for his benefit by million-dollar robots; he believed it deserved to be savored.

He clambered briskly into his EVA suit. Comfortable and easy to use, the suit was the result of six decades’ development from the clumsy armor worn by the Apollo astronauts. And it was smart, too; some said so smart it could go out Moonwalking by itself.

But smart suit or not, Mikhail worked cautiously through a series of manual checks of the suit’s vital systems. He lived alone here at the Moon’s South Pole, save for the electronic omnipresence of Thales, and everybody knew that low gravity made you dumb—the “space stupids,” they called it. Mikhail was well aware of the importance of concentrating on the chores necessary to keep himself alive.

Still, it was only minutes before he was locked tight into the warm enclosure of the suit. Through the slight distortion of his wedge-shaped visor he peered out at his small living quarters. He was a man equipped for interplanetary space, standing incongruously in a clutter of laundry and unwashed dishes.

Then, with a grace born of long practice, he pushed his way out through the airlock, and then the small dustlock beyond, and emerged onto the surface of the Moon.

Standing on the slope of a crater rim mountain, Mikhail was in shadow broken only by sparse artificial lighting. Above him stars crowded a silent sky. When he looked up—he had to lean back in his stiff suit—he could make out dazzling splashes of light high on the crater wall, places the low polar sunlight could reach. Solar-cell arrays and an antenna farm had been placed up there in the light, as well as the sun sensors that were the Station’s main purpose.

This Space Weather Service Station, dug into the wall of a crater called Shackleton, was one of the Moon’s smaller habitats, just a few inflatable domes linked by low tunnels and heaped over by a layer of charcoal-gray Moon dust.

Unprepossessing the hab itself may have been, but it was situated in one of the Moon’s more remarkable locations. Unlike the Earth, the Moon’s axis has no significant tilt; there are no lunar seasons. And at the Moon’s South Pole the sun never rises high in the sky. There the shadows are always long—and, in some places, permanent. Thus the pool of darkness in which Mikhail stood had been unbroken for billions of years, save by humans.

Mikhail looked down the slope, beyond the low bulges of the Station domes. On Shackleton’s floor floodlights revealed a complex tangle of quarries and lumbering machines. Down there robots toiled over the real treasure of this place: water.

When the Apollo astronauts had brought home their first dusty Moon rocks, the geologists had been dumbfounded that the samples contained not a trace of water, not even bound chemically into the mineral structures. It took some decades to unravel the truth. The Moon was no sister world of Earth but a daughter, created in the early days of the solar system when a collision with another infant world had smashed apart a proto-Earth. The debris that had eventually coalesced into the Moon had been superheated until it glowed blue-white, in the process driving off every trace of water. Later, comets had splashed on the Moon’s surface. Out of the billions of tonnes of water delivered by these lesser impacts, most had been lost immediately. But a trace, just a trace, had found its way to the permanently shadowed floors of the polar craters, a gift of water to the Moon as if in recompense for the circumstances of its birth.

By Earth’s standards the Moon’s water was little enough—not much more than a respectably sized lake—but for human colonists it was a treasure beyond price, literally worth far more than its weight in gold. It was invaluable for the scientists too, as it bore a record of eons of cometary formation, and offered indirect clues to the formation of Earth’s oceans, which had also been bequeathed by cometary impacts.

Mikhail’s interest in this place was not lunar ice, however, but solar fire.

He turned away from the shadows and began to toil up the steepening slope of the rim mountain toward the light. The path was just a trail, beaten flat by human footprints. It was marked by streetlights, as everybody called them, small globe lamps hung from poles, so he could see what he was doing.

The slope was steep, each step an effort even in the Moon’s gentle one-sixth gravity. His suit helped, with a subtle hum from exoskeletal servos and a high-pitched whir of the fans and pumps that labored to keep his faceplate clear of condensed sweat. He was soon breathing hard, and his muscles ached pleasantly: this walk was his daily constitutional.

At last he reached the summit of the mountain and emerged into flat sunlight. A small collection of robot sensors huddled here, peering with unending electronic patience at the sun. But the light was too brilliant for Mikhail’s eyes, and his visor quickly opaqued.

The view around him was still more dramatic, and complex. He was standing on the rim of Shackleton, itself a comparatively minor crater, but here at its western rim Shackleton intersected the circles of two other craters. The landscape was jumbled on a superhuman scale: even the craters’ far rims were hidden by the Moon’s horizon. But with long practice Mikhail had trained himself to make out the chains of mountains, slowly curving, that marked the perimeters of these overlapping scars. And all this was thrown into stark relief by the low light of the sun as it rolled endlessly around the horizon, the long shadows it cast turning like clock hands.

The South Pole, shaped when the Moon was young by an immense impact that had bequeathed it the deepest crater in all the solar system, was the most contorted landscape on the Moon. A greater contrast to the flat basalt plain of Tranquillity where Armstrong and Aldrin had first landed, far to the north close to the Moon’s equator, would be hard to imagine.

And this peak was a special place. Even here among the mountains of the Pole, most places knew some night, as the passing shadows of one crater wall or another blocked out the light. But the peak on which Mikhail stood was different. Geological chance had left it steeper and a little taller than its cousins to either side, and so no shadow ever reached its summit. While the Station, only footsteps away, was in perpetual darkness, this place was in permanent sunlight; it was the Peak of Eternal Light. There was nowhere like this on tipped-over Earth, and only a handful of locations like it on the Moon.

There was no morning here, no true night; it was no wonder that Mikhail’s personal clock drifted away from the consensus of the rest of the Moon’s inhabitants. But it was a strange, still landscape that he had grown to love. And there was no better place in the Earth–Moon system to study the sun, which never set from this airless sky.

But today, as he stood here, something troubled him.

Of course he was alone; it was inconceivable that anybody could sneak up on the Station without a hundred automatic systems alerting him. The silent sentinels of the solar monitors showed no signs of disturbance or change, either—not that a cursory eyeball inspection of their casings, wrapped in thick meteorite shielding and Kevlar, would have told him anything. So what was troubling him? The stillness of the Moon was an uncomfortable place to be having such feelings, and Mikhail shivered, despite the comfortable warmth of his suit.

Then he understood. “Thales. Show me the sun.”

Closing his eyes, he lifted his face toward the glare.

When he opened his eyes Mikhail inspected a strange sun.

The center of his faceplate had blocked much of the light of the main disk. But he could make out the sun’s atmosphere, the corona, a diffuse glow spreading over many times the sun’s diameter. The corona had a smooth texture that always reminded him of mother-of-pearl. But he knew that that smoothness masked an electromagnetic violence that dwarfed any human technology—indeed, a violence that was a principal cause of the damaging space weather he had devoted his own life to monitoring.

At the center of the corona he made out the disk of the sun itself, reduced by the visor’s filters to a sullen, coal-like glow. He called for magnification and could make out a speckling that might be granules, the huge convection cells that tiled the sun’s surface. And just visible near the very center of the disk, he made out a darker patch—obviously not a granule, but much more extensive.

“An active region,” he murmured.

“And a big one,” Thales replied.

“I don’t have my log to hand… Am I looking at 12687?” For decades humans had been numbering the active regions they observed on the sun, the sources of flares and other irritations.

“No,” Thales said smoothly. “Active Region 12687 is subsiding, and is a little farther west.”

“Then what—”

“This region has no number. It is too new.”

Mikhail whistled. Active regions usually took days to develop. By studying the resonances of the sun, immense slow sound waves that passed through its structure, you could usually spot major regions on the far side, even before the star’s stately rotation brought them into view. But this beast, it seemed, was different.

“The sun is restless today,” Mikhail murmured.

“Mikhail, your tone of voice is unusual. Did you suspect the active region was there before you asked for the display?”

Mikhail had spent a lot of time alone with Thales, and he thought nothing of this show of curiosity. “One gets an instinct for these things.”

“The human sensorium remains a mystery, doesn’t it, Mikhail?”

“Yes, it does.”

Out of the corner of his eye Mikhail spotted movement. He turned away from the sun. When his faceplate cleared he made out a light, crawling toward him through the lunar shadows. It was a sight almost as unusual, for Mikhail, as the face of the troubled sun.

“It seems I have a visitor. Thales, you’d better make sure we have enough hot water for the shower.” He began to pick his way back down the trail, taking care to plan every step in advance despite his mounting excitement. “This looks like it’s going to be quite a day,” he said.

3: ROYAL SOCIETY

Siobhan McGorran sat alone in a deep armchair. She had her personal softscreen unrolled on her lap, a cup of rather bitter coffee on the occasional table at her side, and her phone clamped to her ear. She was rehearsing the lecture she was to give to an audience of her most distinguished peers in less than half an hour.

She read aloud, “ ‘2037 promises to be the most significant year for cosmology since 2003, when the basic components of the universe—the proportions of baryonic matter, dark matter, and dark energy—were first correctly determined. I was eleven years old in 2003, and I remember how excited I was when the results from the Wilkinson Microwave Anisotropy Probe came in. I suppose I wasn’t a very cool teenager! But to me, MAP was a robot Columbus. That intrepid cosmology probe was sent off in the hope of finding a dark-matter China, but en route it stumbled over a dark-energy America. And just as Columbus’s discoveries fixed the geography of Earth forever in human minds, so we learned the geography of the universe in 2003. Now, in 2037, thanks to the results we anticipate from the latest Quintessence Anisotropy Probe, we—’ ”

The room lights blinked, making her stumble in her reading.

She heard her mother tut. “And so on and so forth,” Maria said, her soft Irish lilt exaggerated by the phone’s tiny speaker. “In time, after a lot of technical guff about this old spaceship nobody remembers, I suppose you’ll grope your way back to the point.”

Siobhan suppressed a sigh. “Mother, I’m the Astronomer Royal, and this is the Royal Society. I’m making the keynote speech! ‘Technical guff’ is expected.”

“And you never were very good at analogies, dear.”

“You could be a bit supportive.” She sipped her coffee, taking care not to spill a drop on her best suit. “I mean, look where your little girl is today.” She flicked on her phone’s vision options so her mother could see.

These were the City of London Rooms in the Royal Society’s offices in Carlton Terrace. She was immersed in rich antiquity, with chandeliers overhead and a marble fireplace at her side.

“What a lovely room,” Maria murmured. “You know, we have a lot to thank the Victorians for.”

“The Royal Society is a lot older than the Victorians—”

“There are no chandeliers here, I can tell you,” Maria said. “Nothing but smelly old people, myself included.”

“That’s demographics for you.”

Maria was in Guy’s Hospital, close to London Bridge, only a few hundred meters from Carlton Terrace. She was waiting for an appointment concerning her skin cancers. For people who had grown old under a porous sky it was a common complaint, and Maria was having to queue.

Siobhan heard raised voices in the background. “Is there a problem?”

“A ruckus at the drinks machine,” Maria said. “Somebody’s credit-chip implant has been rejected. People are a bit excitable generally. It’s a funny sort of day, isn’t it? Something to do with the odd sky, maybe.”

Siobhan glanced around. “It’s not much calmer here.” As the start of the conference had approached, she had been grateful to be left alone with her coffee and a chance to run through her notes, even if she had felt duty-bound to call her mother at Guy’s. But now everybody seemed to be crowding at the window, peering out at the odd sky. It was an amusing sight, she supposed, a clutch of internationally renowned scientists jostling like little kids trying to glimpse a pop star. But what were they looking at?

“Mother—what ‘odd sky’?”

Maria replied caustically, “Maybe you should go take a look yourself. You are the Astronomer Royal, and—” The phone connection fizzed and cut out.

Siobhan was briefly baffled; that never happened. “Aristotle, redial, please.”

“Yes, Siobhan.”

Her mother’s voice returned after a couple of seconds. “Hello?…”

“I’m here,” Siobhan said. “Mother, professional astronomers don’t do much stargazing nowadays.” Especially not a cosmologist like Siobhan, whose concern was with the universe on the vastest scales of space and time, not the handful of dull objects that could be seen with the naked eye.

“But even you must have noticed the aurora this morning.”

Of course she had. In midsummer Siobhan always rose about six, to get in her daily quota of jogging around Hyde Park before the heat of the day became unbearable. This morning, even though the sun had long been above the horizon, she had seen that subtle wash of crimson and green in the northern sky—clearly three-dimensional, bright curtains and streamers of it, an immense structure of magnetism and plasma towering above the Earth.

Maria said, “An aurora is something to do with the sun, isn’t it?”

“Yes. Flares, the solar wind.” To her shame, Siobhan found she wasn’t even sure if the sun was near the maximum of its cycle right now. Some Astronomer Royal she was proving to be.

Anyhow, though the aurora was undeniably a spectacular sight, and it was very unusual to be so bright as far south as London, Siobhan knew it was nothing but a second-order effect of the interaction of solar plasma with the Earth’s magnetic field, and therefore not particularly interesting. She had continued her jogging, not at all motivated to join the rows of slack-jawed dog walkers staring at the sky. And she certainly wasn’t sorry she missed the brief panic as people had assailed the emergency services with pointless calls, imagining London was on fire.

Everybody was still at the window. It was all a bit strange, she conceded.

She set aside her coffee and, phone in hand, walked up to the window. She couldn’t see much past the shoulders of jostling cosmologists: a glimpse of green from the park, a washed-out blue sky. The window was sealed shut to allow the air-conditioning to work, but she thought she could hear a lot of traffic noise: the blaring of horns, sirens.

Toby Pitt spotted her at the back of the pack. A big, affable bear of a man with a strangulated Home Counties accent, Toby worked for the Royal Society; he was the manager of the conference today. “Siobhan! I won’t make jokes about the Astronomer Royal being the last to show any interest in the sky.”

She showed him her phone. “No need. My mother’s already been there.”

“It’s quite a view, though. Come and see.” He extended his massive arm around her shoulders and, with a skillful combination of physical presence and smiling tact, managed to shepherd her through the crowd to the window.

The City of London Rooms had a fine view of the Mall, and of St. James’ Park beyond. The grass of the park glowed lurid green, no longer a native specimen but a tough, thick-leaved drought-resistant breed imported from southern Texas, and the relentless sprinklers sent sprays of water shimmering into the air.

But the traffic in the Mall was jammed. The smart cars had calmly packed themselves up in an optimal queuing pattern, but their frustrated drivers were pounding at their horns, and heat haze rose in a shimmer in the humid air. Looking up the road Siobhan saw that the traffic control lights and lane guides were blinking, apparently at random: no wonder the traffic was snarled.

She looked up. The sun, riding high, flooded the cloudless air with light. Even so, when she shielded her eyes she could still make out a tracery of auroral bands in the sky. She became aware of a noise beyond the blare of the traffic in the Mall, a softer din, muffled by the thick sealed window. It was a growl of frustrated driving that seemed to be rising from across the city. This snarl-up wasn’t local, then.

For the first time that day she felt a flicker of unease. She thought of her daughter, Perdita, at college today. Perdita, twenty years old, was a sensible young adult. But still…

There was a new silence, a shift in the light. People stirred, perturbed. Glancing over her shoulder Siobhan saw that the room lights had failed. That subtle change in the ambient noise must mean the air-conditioning had packed up, too.

Toby Pitt spoke quickly into a phone. Then he held up his hands and announced, “Nothing to worry about, ladies and gentlemen. It isn’t just us; the whole of this part of London seems to be suffering something of a brownout. But we have a backup generator that should be coming online soon.” He winked at Siobhan and said softly, “If we can persuade the ratty old thing to start up in the first place.” But he raised his phone to his ear again, and concern creased his face.

In the heat of the June day, thirty-plus degrees Celsius, the room was already warming up, and Siobhan’s trouser suit was starting to feel heavy and uncomfortable.

From beyond the window there was a crumpling noise, a series of pops, like small fireworks, and a din of wailing car alarms. The cosmologists gasped, a collective impulse. Siobhan pushed forward to see.

That queue of traffic on the Mall was just as stationary as before. But the cars had lurched forward, each smashing into the one in front like a gruesome Newton’s cradle. People were getting out of their vehicles; some of them looked hurt. Suddenly the jam had turned from an orderly inconvenience into a minor disaster of crumpled metal, leaking lubricants, and scattered injuries. There was no sign of police or ambulances.

Siobhan was baffled. She had literally never seen anything like it. All cars nowadays were individually smart. They took data and instructions from traffic control systems and navigational satellites, and were able to avoid cars, pedestrians, and other obstacles in their immediate surroundings. Crashes were virtually unheard of, and traffic deaths had dwindled to a minimum. But the scene below was reminiscent of the motorway pileups that had still blighted Britain during her childhood in the 1990s. Was it possible that all the cars’ electronic guidance systems had failed at once?

Light flared, dazzling her. She flinched, raising her hand. When she could see again, she made out a pall of black smoke, rising from somewhere to the south of the river, its origin lost in murky smog. Then a shock wave reached the Society building. The tough old structure shuddered, and the window creaked. She heard a more remote tinkle of glass, the blaring of alarms, and screams.

It had been an explosion, a big one. The cosmologists murmured, grave and apprehensive.

Toby Pitt touched her shoulder. His face had lost all its humor now. “Siobhan. We’ve had a call from the Mayor’s office. They’re asking for you.”

“Me?…” She glanced around, feeling lost. She had no idea what was happening. “The conference—”

“I think everybody will accept a postponement, in the circumstances.”

“How can I get there? If that mess outside is typical—”

He shook his head. “We can videoconference from here. Follow me.”

As she followed his broad-shouldered form out of the City Rooms, she raised her own phone. “Mother?”

“You’re still there? All I heard was chattering.”

“That’s cosmologists for you. I’m fine, Mother. And you—”

“So am I. That bang was nowhere near me.”

“Good,” Siobhan said fervently.

“I phoned Perdita. The line was bad, but she’s all right. They’re keeping them at college until things settle down.”

Siobhan felt huge, unreasonable relief. “Thank you.”

Maria said, “The doctors are running everywhere. Their pagers seem to be on the blink. You’d think casualties would be coming in but I’ve seen nobody yet… Do you think it was terrorists?”

“I don’t know.” Toby Pitt had reached the door and was beckoning her. “I’ll try to keep the connection open.” She hurried from the room.

4: VISITOR

The rover reached the Station long before Mikhail had clambered his way back down the trail. The visitor waited at the hab entrance with an impatience the surface suit couldn’t disguise.

Mikhail thought he recognized the figure just by his stance. Though its population was scattered around its globe, on the human scale the Moon was a very small town, where everybody knew everybody else.

Thales confirmed it in a whisper. “That is Doctor Eugene Mangles, the notorious neutrino hunter. How exciting.”

That cursed computer-brain is teasing me, Mikhail thought irritably; Thales knows my feelings too well. But it was true that his heart beat a little faster with anticipation.

Encased in their suits, Mikhail and Eugene faced each other awkwardly. Eugene’s face, a sculpture of planed shadows, was barely visible through his visor. He looked very young, Mikhail thought. Despite his senior position Eugene was just twenty-six—a maverick boy genius.

For a moment Mikhail was stuck for something to say. “I’m sorry,” he said. “I don’t get too many visitors out here.”

Eugene’s social skills seemed even more underdeveloped. “Have you seen it yet?”

Mikhail knew what he meant. “The sun?”

“The active region.”

Of course this boy had come here for the sun. Why else visit a solar weather station? Certainly not for the crusty, early-middle-aged astrophysicist who tended it. And yet Mikhail felt a foolish, quite unreasonable pang of disappointment. He tried to sound welcoming. “But don’t you work with neutrinos? I thought your area of study was the core of the sun, not its atmosphere.”

“Long story.” Eugene glared at him. “This is important. More important than you know, yet. I predicted it.”

“What?”

“The active region.”

“From your studies of the core? I don’t understand.”

“Of course you don’t,” Eugene said, apparently careless of any offense he might cause. “I logged my predictions with Thales and Aristotle, date-stamped to prove it. I’ve come here to confirm the data. It’s come to pass, just as I said it would.”

Mikhail forced a smile. “We’ll talk it over. Come inside. You can see as much data as you want. Do you like coffee?”

“They have to listen,” said Eugene.

They?… “About what?”

“The end of the world,” Eugene said. “Possibly.” He led the way into the dustlock, leaving Mikhail standing openmouthed.

They didn’t talk as they worked their way through dustlock and airlock into the hab. Every human on the Moon was still a pioneer, and if you were smart, no matter what was on your mind, as you moved from one safe environment to another through seals and locks and interfaces and in and out of EVA suits, you concentrated on nothing but the life-preserving procedures you were going through. If you weren’t smart, of course, you would be lucky if you were forcibly shipped out before you killed yourself, or others.

Mikhail, slick with daily practice, was first out of his EVA suit. As the suit slithered to its cleaning station—somewhat grotesquely, its servos dragging it across the floor like an animated flayed skin—Mikhail, in his underwear, went to a sink where he scrubbed his hands in a slow trickle of water. The gray-black dust he had picked up handling the suit, grimy despite the dustlock’s best efforts, had rubbed into his pores and under his nails, and was burning slowly with his skin’s natural oils, giving off a smell like gunpowder. The Moon’s dust had been a problem since the first footsteps taken here: very fine, getting everywhere, and oxidizing enthusiastically whenever it got the chance, the dust corroded everything from mechanical bearings to human mucous membranes.

Of course it wasn’t the engineering problems of Moon dust that were on Mikhail’s mind right now. He risked a look around. Eugene had taken off boots and gloves, and he lifted his helmet away, shaking his beautiful head to free up thick hair. That was the face Mikhail remembered, the face he had first glimpsed at some meaningless social function in Clavius or Armstrong—a face freshly hardened into manhood, but with the symmetry and delicacy of boyhood, even if the eyes were a little wild—the face that had drawn him as helplessly as a moth to a candle.

As Eugene stripped off his spacesuit Mikhail couldn’t help dwelling on an old memory. “Eugene, have you ever heard of Barbarella?”

Eugene frowned. “Is she at Clavius?”

“No, no. I mean an old space movie. I’m something of a buff of pre-spaceflight cinema. A young actress called Jane Fonda…” Eugene clearly had no idea what he was talking about. “Never mind.”

Mikhail made his way to the dome’s small shower cubicle, stripped off the last of his clothing, and stood under a jet. The water emerged slowly, in big shimmering low-gravity droplets that fell with magical slowness to the floor, where suction pumps drew in every last precious molecule. Mikhail lifted his face to the stream, trying to calm himself.

Thales said gently, “I’ve brewed some coffee, Mikhail.”

“Thales, that was thoughtful.”

“Everything is under control.”

“Thank you…” Sometimes it really was as if Thales knew Mikhail’s moods.

Thales was actually a less sophisticated clone of Aristotle, who was an intelligence emergent from a hundred billion Earth-side computers of all sizes and the networks that linked them. A remote descendant of the search engines of the late twentieth century, Aristotle had become a great electronic mind whose thoughts crackled like lightning across the wired-up face of the Earth; for years he had been a constant companion to all humankind.

When humans had begun their permanent occupation of the Moon at Clavius Base, it had been inconceivable that they should not take Aristotle with them. But it takes light more than a second to travel from Earth to the Moon, and in an environment where death lurks a single error away, such delays were unacceptably long. So Thales had been created, a lunar copy of Aristotle. Thales was updated continually from Aristotle’s great memory stores—but he was necessarily simpler than his parent, for the electronic nervous system laid across the Moon was still rudimentary compared to the Earth’s.

Simpler or not, Thales did his job. He was certainly smart enough to justify the name he had been given: Thales of Miletus, a sixth-century Greek, had been the first to suggest that the Moon shone not by its own light but by reflection from the sun—and, it was said, he had been the first man to predict a solar eclipse.

For everybody on the Moon, Thales was always there. Often lonely despite his stoical determination, Mikhail had been soothed by Thales’s measured, somewhat emotionless voice.

Right now, thinking wistfully of Eugene, he felt he needed soothing.

He knew that Eugene was based at Tsiolkovski. The huge Farside crater was host to an elaborate underground facility. Buried in the still, cold Moon, undisturbed by tremors, shadowed from Earth’s radio clamor and shielded from all radiation except for a little leakage from trace quantities in the lunar rocks, it was an ideal location for hunting neutrinos. Those ghost-like particles scooted through most solid matter as if it weren’t even there, thus providing unique data about such inaccessible places as the center of the sun.

But how odd to come all the way to the Moon, and then to burrow into the regolith to do your science, Mikhail thought. There were so many more glamorous places to work—such as the big planet-finder telescope array laid out in a North Pole crater, capable of resolving the surfaces of Earth-like planets orbiting suns spread across fifty light-years.

He longed to discuss this with Eugene, to share something of his life, his impressions of the Moon. But he knew he must keep his reactions to the younger man in appropriate categories.

Since his teens, when he had become fully aware of his sexuality, Mikhail had learned to master his reactions: even in the early twenty-first century, homosexuality was still something of a taboo in Vladivostok. Discovering in himself a powerful intellect, Mikhail had thrown himself into work, and had grown used to a life lived largely alone. He had hoped that when he moved away from home, as his career took him through the rest of the sprawling Eurasian Union as far as London and Paris, and then, at last, off the Earth entirely, he would find himself in more tolerant circles. Well, so he had; but by then it seemed he had grown too used to his own company.

His life of almost monastic isolation had been broken by a few passionate, short-lived love affairs. But now, in his midforties, he was coming to accept the fact that he was never likely to find a partner to share his life. That didn’t make him immune to feelings, however. Before today he had barely spoken two words to this handsome boy, Eugene, but that, evidently, had been enough to develop a foolish crush.

He had to put it all aside, though. Whatever Eugene had come to Shackleton for, it wasn’t for Mikhail.

The end of the world, the boy had said. Frowning, Mikhail toweled himself dry.

5: EMERGENCY MANAGEMENT

Siobhan was taken to the Council Room on the first floor of the Royal Society building. The room’s centerpiece was an oval conference table large enough to seat twenty or more, but Siobhan was alone here save for Toby Pitt. She sat at the head of the table uncertainly. On the wall was a slightly surreal Zulu tapestry, meant to show symbolically the rise of science, and portraits of former fellows—mostly dead white males, though the more recent animated images were more diverse.

Toby tapped at the table’s polished surface, which turned transparent to reveal a bank of embedded softscreens. The screens lit up, variously showing scenes of disaster—crashes on the road and rail systems, raw sewage spilling from a pipe onto a beach somewhere, what looked horribly like the wreck of a plane plowed into a Heathrow runway—and concerned faces, most with softscreens in their backgrounds and earpieces clamped to their heads.

One serious-looking young woman seemed to be calling from a police control room. When she caught Siobhan’s eye, she nodded. “You’re the astronomer.”

“The Astronomer Royal, yes.”

“Professor McGorran, my name is Phillippa Duflot.” Perhaps in her early thirties, alarmingly well spoken, she wore a slightly disheveled business suit. “I work in the Mayor’s office; I’m one of her PAs.”

“The Mayor—”

“Of London. She asked me to find you.”

“Why?”

“Because of the emergency, of course.” Phillippa Duflot looked irritated, but she visibly calmed herself; considering the strain she was evidently under, Siobhan thought, her self-control was impressive. “I’m sorry,” Phillippa said. “All this has hit us so suddenly, over the last couple of hours or less. We rehearse for the major contingencies we can think of, but we’re struggling to cope today. Nobody anticipated the scale of this. We’re trying to find our feet.”

“Tell me how I can help you.”

Formally Phillippa was calling on behalf of the London Resilience Forum. This was an interagency body that had been set up following the upsurge in terrorism at the turn of the century. Chaired from the Mayor’s office, it contained representatives of the city’s emergency services, transport, the utilities, the health services, and local government. There was a separate body responsible for London emergency planning, which also reported in to the Mayor. Above such local bodies were national emergency planning agencies, which reported to the Home Office.

Siobhan learned quickly that most of these agencies were talking shops. The real responsibility for emergency responses lay with the police, and right now the key figure in touch with the Mayor was a chief constable. It was the way things were done in Britain, Siobhan gathered; there was a lack of central control, but a local flexibility and responsiveness that generally worked well. But now that Britain was thoroughly integrated into the Eurasian Union there was also a Union-wide emergency management agency, based on the Americans’ FEMA, under whose auspices, some years earlier, firefighters from London had been sent in response to a chemical plant disaster in Moscow.

And today this network of disaster management agencies was buzzing with bad news. London was afflicted by a whole series of interconnected problems, whose root cause Siobhan at first couldn’t guess at. Suddenly, all at once, everything was falling apart.

The most immediate problem was the collapse of the power grid. Phillippa bombarded Siobhan with data on areas of brownout and blackout, and images of the consequences: here was an underground shopping mall in Brent Cross, its lights doused and elevators and escalators stalled, thousands of people trapped in a darkness broken only by a ruddy emergency glow.

Phillippa looked doleful. “The very first call we logged today was from a man trapped in his hotel room when the electronic lock jammed up. Since then it’s just mushroomed. Every transport system has ground to a halt. People are stranded on planes ramped up on runways; others are trapped in planes that can’t land. We don’t even have numbers yet. We don’t dare think how many people are just trapped in lifts!”

The power system was the problem. Electrical power originated in generating stations—these days mostly nuclear, wind-generated, tidal, and a few fossil-fuel-burning relics. The generators sent out rivers of current in transmission cables at high voltages, more than a hundred thousand volts. These were stopped down at local substations and transformers and sent out through more lines, eventually reaching the level of the few hundred volts that reached businesses and homes.

“And now it’s all failing,” Siobhan prompted.

“Now it’s failing.”

Phillippa showed Siobhan an image of a transformer, a unit as big as a house, shaking itself to pieces as its core steel plates crashed and rattled. And here were power lines sagging, smoking, visibly melting, and where they touched trees or other obstacles powerful arcs sparked fires.

This was called magnetostriction, Phillippa said. “The engineers know what’s happening. It’s just that the GICs today are bigger than anything they’ve seen before.”

“Phillippa—what’s a GIC?”

“A geomagnetically induced current.” Phillippa eyed Siobhan with suspicion, as if she shouldn’t have had to explain; perhaps she wondered if she was wasting her time. “We’re in the middle of a geomagnetic storm, Professor McGorran. A huge one. It came out of nowhere.”

A geomagnetic storm: of course, a storm from the sun, the same cause as the beautiful aurora. Siobhan, her brains clogged in the room’s gathering heat, felt dull not to have grasped this at once.

But her basic physics was coming back to her. A geomagnetic storm, a fluctuation of Earth’s magnetic field, would induce currents in power lines, which were simply long conductors. And as the induced currents would be direct, while the generated electrical supply was alternating, the system would quickly be overwhelmed.

Phillippa said, “The generating companies are wheeling—”

“Wheeling?”

“Buying in capacity from outside. We have exchange deals with France, primarily. But the French are in trouble, too.”

“There must be some tolerance in the system,” Siobhan said.

“You’d be surprised,” Toby Pitt said. “For fifty years we have been growing our power demands, but have resisted building new power stations. Then you have market forces, which ensure that every component we do install barely has the capacity to do the job that’s asked of it—and all at the lowest possible cost. So we have absolutely no resilience.” He coughed. “I’m sorry. A hobbyhorse of mine.”

“The worst single problem is the loss of air-conditioning,” Phillippa said grimly. “It isn’t even noon yet.”

In a 2030s British midsummer, heat was a routine killer. “People must be dying,” Siobhan said, wondering; it was the first time it had really struck her.

“Oh, yes,” Phillippa said. “The elderly, the very young, the frail. And we can’t get to them. We don’t even know how many there are.”

Some of the softscreens flickered and went blank. This was the other side of the day’s problems, Phillippa said: communications and electronic systems of all kinds were going down.

“It’s the satellites,” she went on. “The comsats, navigation satellites, the lot—all taking a beating up there. Even land lines are failing.”

And as the world’s electronic interconnectedness broke down, the smart systems that were embedded in everything, from planes to cars to buildings to clothes and even people’s bodies, were all failing. That poor man stuck in his hotel room had only been the first. Commerce was grinding to a halt as electronic money systems failed: Siobhan watched a small riot outside a petrol station where credit implants were suddenly rejected. Only the most robust networks were surviving, such as government and military systems. The Royal Society building happened still to be connected to central services by old-fashioned fiber-optic cables, Siobhan learned; the venerable establishment had been saved by its own lack of investment in more modern facilities.

Siobhan said uncertainly, “And this is another symptom of the storm?”

“Oh, yes. While our priority is London, the emergency isn’t just local, or regional, or even national. From what we can tell—data links are crashing all over the place—it’s global…”

Siobhan was shown a view of the whole world, taken from a remote Earth resources satellite. Over the planet’s night side aurorae were painted in delicate, heartbreakingly beautiful swirls. But the world below was not so pretty. Darkened continents were outlined by the lights of the cities strung along their coasts and the major river valleys—but those necklaces of lights were broken. As each outage triggered problems in neighboring regions, the blackouts were spreading like infections. Power utilities were in some places trying to help each other out, but, Phillippa said, there was conflict; Quebec was accusing New York of “stealing” some of its megawatts. In a few places Siobhan saw the ominous glows of fires.

All this in a couple of hours, Siobhan thought. How fragile the world is.

But the satellite imagery was full of hash, and at last it broke down altogether, leaving a pale blue screen.

“Well, this is dreadful. But what can I do?”

Phillippa again looked suspicious. You need to ask? “Professor McGorran, this is a geomagnetic storm. Which is primarily caused by problems with the sun.”

“Oh. And so you called an astronomer.” Siobhan suppressed an urge to laugh. “Phillippa, I’m a cosmologist. I haven’t even thought about the sun since my undergraduate days.”

Toby Pitt touched her arm. “But you’re the Astronomer Royal,” he said quietly. “They’re out of their depth. Who else are they going to call?”

Of course he was right. Siobhan had always wondered if her royal warrant, and the vague public notoriety that came with it, was worth the trouble. The first Astronomers Royal, men like Flamsteed and Halley, had run the observatory at Greenwich and had spent most of their time making observations of the sun, Moon, and stars for use in navigation. Now, though, her job was to be a figurehead at conferences like today’s, or an easy target for lazy journalists looking for a quote—and, it seemed, an escape route for politicians in a crisis. She said to Toby, “Remind me to quit when this is all over.”

He smiled. “But in the meantime…” He stood up. “Is there anything you need?”

“Coffee if you can get it, please. Water if not.” She raised her own phone to her face; she felt a spasm of guilt that she hadn’t even noticed it had lost its signal. “And I need to speak to my mother,” she said. “Could you bring me a land line?”

“Of course.” He left the room.

Siobhan turned back to Phillippa. “All right. I’ll do my best. Keep the line open.”

6: FORECAST

Dressed in recycled-paper coveralls, Mikhail and Eugene sat in Mikhail’s small, cluttered wardroom.

Eugene cradled a coffee. They were both awkward, silent. It seemed strange to Mikhail that such a handsome kid should be so shy.

“So, neutrinos,” Mikhail said tentatively. “Tsiolkovski must be a small place. Cozy! You have many friends there?”

Eugene looked at him as if he were talking in a foreign tongue. “I work alone,” he said. “Most of them down there are assigned to the gravity-wave detector.”

Mikhail could understand that. Most astronomers and astrophysicists were drawn to the vast and faraway: the evolution of massive stars and the biography of the universe itself, as revealed by exotic signals like gravity waves—that was sexy. The study of the solar system, even the sun itself, was local, parochial, limited, and swamped with detail.

“That’s always been the trouble with getting people to work on space weather, even though it’s of such practical importance,” he said. “The sun–Earth environment is a tangle of plasma clouds and electromagnetic fields, and the physics involved is equally messy.” He smiled. “We’re in the same boat, I suppose, me stranded at the Pole of the Moon, you stuck down a Farside hole, both pursuing our unglamorous work.”

Eugene looked at him more closely. Mikhail had the odd feeling that this was the first time the younger man had actually noticed him. Eugene said, “So what got you interested in the sun?”

Mikhail shrugged. “I liked the practical application. The sky reaching down to the Earth… Most cosmological entities are abstract and remote, but not the sun. And besides, we Russians have always been drawn to the sun. Tsiolkovski himself, our great space visionary, drew on sun worship in some of his thinking, so it’s said.”

“Maybe it’s because you don’t get to see much of it so far north.”

Mikhail was taken aback. Was that an actual joke? He forced a laugh. “Come,” he said, standing. “I think it’s time we visited the monitor room.”

They had to pass through a short, low tunnel to another dome. And in the monitor room, the younger man stared around, openmouthed.

The room was a twenty-first-century shrine to Sol. Its walls were coated by glowing softscreens that showed images of the sun’s surface or its atmosphere, or the space between Earth and sun, crowded with dynamic structures of plasma and electromagnetism, or Earth itself and its complicated magnetosphere. The images were displayed in multiple wavelengths—visible light, hydrogen light, calcium light, infrared and ultraviolet, at radio wavelengths—each of them revealing something unique about the sun and its environment. Even more instructive to eyes trained to see were the spectral analyses, spiky graphs that laid bare the secrets of Earth’s star.

This was a graphic summary of the work of the Space Weather Service. This lunar post was just one of a network of stations that monitored the sun continually; there were sister stations on all the continents of Earth, while satellites swarmed on looping orbits around the sun. Thus the Service kept myriad eyes trained on the sun.

It was necessary work. The sun has been shining for five billion years, breathing out heat and light and the solar wind, a stream of high-energy charged particles. But it is not unchanging. Even in normal times the solar wind is gusty; great streamers of it pour out of coronal holes, breaks in the sun’s outer atmosphere. Meanwhile sunspots, cooler areas dominated by tangles of magnetic fields, were noticed by humans on the sun’s surface as early as the fourth century before Christ. From such troubled areas, flares and immense explosions can spew high-frequency radiation and fast-moving charged particles out into space. All this “weather” batters against the layers of air and electromagnetism that shield the Earth.

Through most of human history this went unnoticed, save for the marvelous aurorae irregularly painted over the sky. But if humans aren’t generally vulnerable to the storms in space, the electrical equipment they develop is. By 2037 it was nearly two centuries since solar-induced currents in telegraph lines had started to cause headaches for their operators. Since then, the more dependent the human world became on its technology, the more vulnerable it became to the sun’s tantrums—as Earth was learning that very day.

For a fragile, highly interconnected high-technology civilization, living with a star, it had been learned, was like living with a bear. It might not do you any harm. But the least you had to do was watch it, very carefully. And that was why the Space Weather Service had been set up.

Though now led by the Eurasian Union, the Space Weather Service had developed from humbler beginnings in the twentieth century, starting with the Americans’ Space Environment Center, a joint enterprise of such agencies as NASA, the National Oceanic and Atmospheric Administration, and the Department of Defense.

“Back then the data gathered were patchy,” Mikhail said. “Scavenged from science satellites dedicated to other purposes. And forecasting was just guesswork. But a few solar-storm disasters around the solar max of 2011 put paid to that. These days we have a pretty comprehensive data set, continually updated in real time. The forecasting systems are big numerical-prediction suites based on magneto-hydrodynamics, plasma physics, and the like. We have a complete chain of theoretical modeling from the surface of the sun to the surface of the Earth—”

But Eugene wasn’t listening. He tapped a hydrogen-light image. “That is the problem,” he said.

It was the new active region. Visibly darker than the surrounding photosphere, it was an ugly S-shaped scar. “I admit it’s a puzzle,” Mikhail said. “At this stage of the solar cycle you wouldn’t expect something like that.”

“I expected it,” Eugene said. “And that’s the whole point.”

Carefully Mikhail said, “The end of the world?”

“Not today. Today is just a precursor. But it will be bad enough. That’s why I’ve come here. You have to warn them.” His eyes were huge and dark, haunted. “I have time-stamped predictions.”

“You told me that.”

“Even so they won’t pay any attention to me. But they will listen to you. After all, this is your job. And now that you’ve got proof, you’ll have to do it, won’t you? You’ll have to warn them.”

Eugene really had no social skills at all, Mikhail thought, with a mix of resentment and pity. “Who are they? Who exactly do you want me to warn?”

Eugene spread his hands. “For a start, everybody vulnerable. On the Moon. On the Space Station. On Mars, and aboard Aurora 2.”

“And on Earth?”

“Oh, yes. And Earth.” Eugene glanced at his watch. “But by now Earth is already being hit.”

Mikhail studied his face for a long moment. Then he called for Thales.

7: MASS EJECTION

Siobhan worked the screens in the conference table, seeking information.

It wasn’t easy. Solar studies and space weather simply weren’t in Siobhan’s domain of specialty. Aristotle was able to help, though he seemed somewhat absentminded at times; she realized uneasily that the erosion of the world’s interconnectivity, on which he was based, had to be affecting him, too.

She quickly discovered that there were solar observatories all over the world, and off it. She tried to get through to Kitt Peak, Mauna Kea in Hawaii, and the Big Bear observatory in southern California. She didn’t reach a human being in any of these sites, predictably enough; even if the comms systems weren’t down, they were no doubt already overwhelmed with calls. But she did learn of the existence of a “Space Weather Service,” a network of observatories, satellites, data banks, and experts that monitored the sun and its stormy environs, and tried to predict the worst of its transgressions. There was even a weather station at the South Pole of the Moon, it seemed.

Despite decades of watching the moody sun, though, only one person had predicted today’s unusual events, a young scientist on the Moon called Eugene Mangles, who had logged quite precise forecasts on a few peer-review sites. But the Moon was out of touch.

Thirty minutes after last speaking with her, Siobhan called Phillippa Duflot again.

“It’s all to do with the sun,” she began.

Phillippa said, “We know that much—”

“It has given off what the sungazers call a ‘coronal mass ejection.’ ”

She described how the corona, the sun’s extended outer atmosphere, is held together by powerful magnetic fields rooted in the sun itself. Sometimes these fields get tangled up, often over active regions. Such tangles will trap bubbles of superheated plasma, emitted by the sun, and then violently release them. That was what had happened this morning, over the big sunspot continent the experts were calling Active Region 12688: a mass of billions of tonnes of plasma, knotted up by its own magnetic field, had been hurled from the sun at a respectable fraction of the speed of light.

“The ejection took less than an hour to get here,” Siobhan said. “I understand that’s fast, for such phenomena. Nobody saw it coming, and nobody was particularly expecting it to happen at this stage of the sun’s cycle anyhow.” Except, she made a mental note, that lone astronomer on the Moon.

Phillippa prompted, “So this mass of gas headed for the Earth—”

“The gas itself is sparser than an industrial vacuum,” Siobhan said. “It’s the energy contained in its particles and fields that has done the damage.”

When it hit, the mass ejection had battered at the Earth’s magnetic field. The field normally shields the planet, and even low-orbiting satellites, but today the mass ejection had pushed the field down beneath the orbits of many satellites. Exposed to waves of energetic solar particles, the satellites’ systems absorbed doses of static electricity that discharged wherever they could.

“Imagine miniature lightning bolts sparking around your circuit boards—”

“Not good,” Phillippa said.

“No. Charged particles also leaked into the upper atmosphere, dumping their energy on the way—that was the cause of the aurorae. And Earth’s magnetic field suffered huge variations. Perhaps you know that electricity and magnetism are linked. A changing magnetic field induces currents in conductors.”

Phillippa said hesitantly, “Is that how a dynamo works?”

“Yes! Exactly. When it fluctuates, Earth’s field causes immense currents to flow in the body of the Earth itself—and in any conducting materials it can find.”

“Such as our power distribution networks,” Phillippa said.

“Or our comms links. Hundreds of thousands of kilometers of conducting cables, all suddenly awash with fast-varying, high-voltage currents.”

“All right. So what do we do about it?”

“Do? Why, there’s nothing we can do.” The question seemed absurd to Siobhan; she had to suppress an unkind impulse to laugh. “This is the sun we’re talking about.” A star whose energy output in one second was more than humankind could muster in a million years. This mass ejection had caused a geomagnetic storm that went far off the scales established by the patient solar weather watchers, but to the sun it was nothing but a minor spasm. Do, indeed: you didn’t do anything about the sun, except keep out of its way. “We just have to sit it out.”

Phillippa frowned. “How long will it last?”

“Nobody knows. This is unprecedented, as far as I can make out. But the mass ejection is fast moving and will pass over us soon. Only hours more, perhaps?”

Phillippa said earnestly, “We need to know. It’s not just power we have to think about. There’s sewage, the water supply…”

“The Thames barrier,” Toby said. “When is high tide?”

“I don’t know,” Phillippa said, making a note. “Professor McGorran, can you try to nail down a timescale?”

“Yes, I’ll try.” She closed down the link.

“Of course,” Toby said to Siobhan, “the sensible thing to do would be to build our systems more robustly in the first place.”

“Ah, but when have we humans ever been sensible?”

Siobhan continued to work. But as time wore on the comms links only worsened.

And she was distracted by more images.

Here was an immense explosion in the great trans-European pipeline that nowadays brought Britain most of its natural gas. Like cables, pipelines were also conductors thousands of kilometers long, and the currents induced in them could increase corrosion to the point of failure. Pipelines were grounded at frequent intervals to avert this problem. But this pipeline, a very modern structure, had been made of ethylene for economy’s sake, and was a good deal easier to ignite. Numbly Siobhan studied the statistics of this one incident: a wall of flame a kilometer wide, trees felled for hundreds of meters around, hundreds feared dead… She tried to imagine such horror multiplied a thousandfold around the world.

And it wasn’t just humans and their technological systems that were affected. Here was a random bit of news of flocks of birds apparently losing their way, and a haunting image of whales beached on a North American shore.

Toby Pitt brought her a phone, a clunky set trailing a cord. “I’m sorry it took so long,” he said.

The phone must have been at least thirty years old, but, connected to the Society’s reliable fiber-optic backup lines, it worked, more or less. It took her a few tries to get through to Guy’s, and then to persuade a receptionist to find her mother.

Maria sounded scared, but in control. “I’m fine,” she insisted. “The power outages have just been blinks; the emergency system is working well. But things are very strange here.”

Siobhan nodded. “The hospitals must be overwhelmed. Heat victims—the accidents in traffic—”

“Not just that,” Maria said. “People are coming in because their pacemakers are playing up, or their servo-muscles, or bowel control implants. And there’s a whole flood of heart attack victims, it seems to me. Even people with no implants at all.”

Of course, Siobhan mused. The human body itself is a complex system controlled by bioelectricity, itself subject to electrical and magnetic fields. We are all tied to the sun, she thought, like the birds and the whales, tied by invisible lines of force nobody even suspected existed a couple of centuries ago. And we are so very vulnerable to the sun’s tantrums, even our very bodies.

Toby Pitt said, “Siobhan, I’m sorry to interrupt. You’ve another call.”

“Who is it?”

“The Prime Minister.”

“Good Lord.” She thought it over, and asked, “Which one—?”

The phone came alive in her hand. As electricity jolted into her body the muscles of her right arm turned rigid. Then the phone shot from her grasp and slid over the table, showering blue sparks.

19: INDUSTRY

Bud Tooke met Siobhan off the Komarov, just as before.

She had already told Bud she wanted to get straight to work, no matter the local time of day. He smiled as he rode with her to the main domes. “No sweat. We’re working a twenty-four-hour-a-day shift here anyhow—have been for six months, ever since the President’s directive came in.”

“It’s appreciated back home,” she said warmly.

“I know. But it’s not a problem. We’re all highly motivated up here.” He sniffed up a deep breath, expanding his chest. “A challenge is energizing. Good for you.”

Siobhan had felt on the edge of exhaustion for the last six months. She said dubiously, “I guess so.”

He eyed her, concern penetrating his military brusqueness. “So how was the trip?”

“Long. Thank God for Aristotle, and e-mail.”

This was Siobhan McGorran’s third trip to the Moon. Her first voyage had been wonderful, something she had dreamed of as a child. Even the second had been exciting. But the third was just a chore—and time consuming at that.

The trouble was, here they were, halfway through 2038, a whole year after June 9, already six months since Alvarez had made her epochal Christmas announcement—and now less than four years before sunstorm day. Siobhan knew intellectually, from her Gantt charts and dependency diagrams and critical paths, that the various subprojects of the mighty shield program were actually going quite well. But inside her head a calendar-clock ticked steadily down.

She tried to explain to Bud. “I’m a natural pessimist,” she said. “I expect things to go wrong, and am suspicious when they go well.” She forced a smile. “Some attitude for a leader.”

He angled his head so his frosting of crew-cut hair caught the corridor strip lights. “You’re doing fine. Anyhow, when it comes to motivation, leave that to me. I was once a pain-in-the-butt sergeant at training camps in the Midwest. I can get them down and dirty. Maybe between us we’ll turn out to be a good team.” And he put his arm around her shoulders and gave her a squeeze.

She could feel his strength, and detected a scent of aftershave. Bud did sometimes seem like a relic of the 1950s. But his indomitability, straightforwardness, and sheer good humor were very welcome. All of which was rationalizing, of course.

As he held her, she felt a deep and pleasant warmth spread out through her belly and rise to her face. She was sorry when the brief hug ended.

On her first visit, Artemis Dome had been a scene of lunar industrial experiments. Now, just a few months later, the scale of the operation had changed utterly. The dome had been sliced open and crude extensions built on it to provide a lot more acreage of processing facility, most of it in vacuum. It was an infernal scene, Siobhan thought, with grotesque spacesuited figures gliding through banks of pipes, ducts, and metallic vessels, and everything stained the ubiquitous charcoal gray of the Moon, like a caricature of the darkest days of England’s Industrial Revolution.

The product of this mighty effort was metal.

Aluminum was the main structural component of the mass driver launch system, while iron would be required for the electromagnetic systems that would be its working muscles. But the mass driver was going to be kilometers long. The lunar colonists were having to jump straight from a trialed process to industrial-scale production; the scale change was tremendous, the pressure immense.

Bud sketched some of the difficulties. “These are tried-and-tested processes on Earth,” he said. “But up here nothing behaves the same, not a heap of ball bearings or oil flowing in a pipe…”

“But you’re getting there.”

“Oh, yes.”

Meanwhile Selene Dome, once the Moon’s first farm, had been turned into a glass factory. It was simple: you pushed lunar regolith in one end, applied focused solar heat, and drew glass out the other end, shimmering hot, to be molded into prefabricated sections.

Bud said, “Every time a journalist gets through to me, I’m asked the same damn question: why are we making the infrastructure of the shield from lunar glass? And every time I have to give the same answer: because this is the Moon. And wonderful though it is, the Moon doesn’t give you a lot of choice.”

The Moon’s peculiar composition was dictated by its formation. The NASA geologists who had studied the first samples returned by the Apollo astronauts had been puzzled: this iron-deficient, volatile-free stuff seemed quite unlike the rocks of Earth’s crust. It was more like the material of Earth’s mantle, the thick layer between crust and core. It turned out that this was because the Moon was made of Earth’s mantle—or rather, of the great gout of it that had been splashed away by that primordial, Moon-making impact.

“And so that’s what we’re left with,” Bud said. “Igneous rocks make up ninety percent of the crust here. It’s as if we were learning to live on the slopes of Vesuvius. And there’s virtually no water, remember. Without water you can’t make concrete, for instance.”

“Hence glass.”

“Hence glass. Siobhan, glass grows naturally on the Moon. Wherever a meteor falls, the regolith fuses, and glass is splashed everywhere. So that’s what we use.

“And here’s the finished product.” With a showman’s flourish he pointed to glass components, some of them many times a person’s height, stacking up in a rudimentary store out in the vacuum. “There are no prototypes here, no test articles. Everything we make is intended to be launched; everything we build will wind up on the shield—everything you see here will fly. The designs they feed us from Earth keep changing, and we’re trying to optimize our manufacturing too, aiming for the minimum weight to provide a given structural strength. So the final shield will be a funny sort of hybrid, with the last components, five years younger, looking quite different from the first. But we’ll just have to cope with that.”

Siobhan gazed at the glass sections with genuine awe. They looked like nothing much, like buttresses for a fairground ride or a fancy trade-show exhibit. But these odd-looking struts of glass, and tens of thousands of others just like them, were to be shot into space, where they would be assembled to form the scaffolding of a mirror wider than the planet. Her wild back-of-the-envelope concept was already coming into physical actuality. She felt thrilled.

Bud was watching the workers beyond the window. “You know,” he said, “I think this could be the making of this crew. Before June 9 we were kind of playing up here, playing at being lunar colonists. Now we’ve got a sense of urgency, a specific goal, a schedule to fulfill. I believe this event will push forward the program of the colonization and exploitation of the Moon by decades, or more.”

That meant little to her, but she saw how important it was to Bud. “That’s wonderful.”

“Yes. But,” he added heavily, “sometimes I walk on eggshells.”

“Why?”

“Because this isn’t what these guys came here for. They’re mostly scientists, remember. Suddenly they’ve been drafted to work on an assembly line. Yes, there’s dynamism and adrenaline. But sometimes they remember their old lives, and they feel—”

“Resentful?”

“Well, I can take that. The worst thing is, they get bored. The disadvantage of overeducation. As long as I can keep them distracted we get along fine.” He peered out, the laugh lines around his eyes catching the light, and she thought he seemed very fond of his temperamental workers.

“Come on,” she said. “You haven’t shown me Hecate yet.”

As they walked on, she slipped her hand into his.

Later he took her out of Clavius Base to see David’s Sling.

As they approached the site of the Sling, Siobhan stood up in the surface tractor’s bubble-dome pressure compartment to see better. Only three kilometers of the launcher had been completed, of a projected thirty. Even so, it was an astonishing sight: in the low sunlight, under a pitch-black sky and against a gray-brown backdrop of Moon dust, the launcher shone like a sword.

The engineers called it a mass driver, or an electromagnetic launcher—or, more simply, a space gun. The heart of it was an aluminum track standing on trestle legs, thin and light like all lunar constructions. Wrapped around the track was a coil of iron, a vast spiral that Bud called the solenoid. At the loading end spacesuited figures moved cautiously around a crane, which was hoisting a glistening pellet up onto the track. The track stretched away across the level floor of Clavius, soon passing out of sight beyond the Moon’s close horizon.

“The principle is simple,” Bud said. “It’s a cannon driven by electromagnetism. You wrap your cargo in a blanket of iron—which we can reuse, by the way. You put your cargo pellet on the rail. The magnetic field, generated from that blockhouse over there”—he pointed at a nondescript dome—“then pulses through the solenoid, and your pellet is pushed along the track.” The changing magnetic field induced electric currents in the iron blanket, and the currents then pushed against the magnetism: “It’s just the principle of the electric motor,” Bud said.

As he spoke he pressed his hand against the small of her back with a pleasing familiarity.

She prompted, “And after thirty kilometers of accelerating—”

“You have escape velocity, without the need for any of that messy business of rockets and launch pads and countdowns. And then you can go wherever you want—fall all the way down to Earth, even.”

“It’s really a fantastic conception,” she said.

“Yeah. But like most of what we do on the Moon, people figured it all out long before they had a chance to get here to build it. The idea of an electromagnetic launcher dates back to the 1950s, I think. A science fiction writer. Famous in his day…”

“Couldn’t you build a mass driver on Earth?”

“Yeah. In principle. But the air would be a problem. You would be flying at interplanetary speeds a meter above the ground. On Earth, at escape velocity, Mach 20 or 25, you’d burn up. But up here there’s no air, so no air resistance. Then we have our famous low gravity, so the speeds we need to acquire are much less than on Earth: down there you’d need a launcher twenty times as long as this one—maybe six hundred kilometers. As for power, all that lovely sunlight falls down from the sky for free. But the real economy comes from the fact that unlike with rocket technology, all our launch equipment stays bolted to the ground, where it belongs. With the Sling, we can get off this rock for pennies per kilogram.”

He started to wax enthusiastically about the opportunities the Sling and its more sophisticated successors would one day give to the Moon. “From here we can send heavy-lift components to the Lagrange points, or Earth orbit, or to the planets and beyond, for a fraction of the effort and cost of launching from Earth. Once people dreamed that the Moon would be the stepping-stone to opening up the solar system. Those dreams died when it was found that the Moon has only a trace of water. But this is how the dream will live again.”

She touched his arm a little wistfully. She relished his passion, his energy. But he was oddly like Eugene Mangles, in a way: as Eugene’s obsession was his work, so Bud’s was evidently the Moon and its future—to the exclusion of herself, she thought. “Bud,” she said. “You sold me. But for now, all I want the Moon to do is to save the Earth.”

“We’re working on it. Even though we all know it won’t be enough.”

The shield couldn’t provide perfect cover. It had had to be designed to block the sunstorm’s peak-energy bombardment in the visible light spectrum, but could do nothing about an anticipated accompaniment of X-rays, gamma rays, and other nasties, peripheral in terms of the storm’s total output, but potentially devastating for the Earth. “We couldn’t do it all,” she said.

“I know. I keep telling my folk that. But even so it doesn’t feel enough, whatever we do… Look. I think they’re ready for a test.”

The cargo pellet was in place on the gleaming track. The crane withdrew. She saw the pellet start to move: slowly at first, a ponderous start that told of its mass, and then more rapidly. That was all there was to it. There were no special effects: no flaring fire, no billowing smoke. But as the generators poured their energies into the launcher she felt a tingle in her gut, perhaps some biochemical response to the mighty currents flowing just a few hundred meters away.

The pellet, still accelerating, shot out of sight.

Bud clenched a fist. “Today all we can do is dig another hole in Clavius’s floor. But in six months tops we’ll be firing to orbit. Imagine riding that thing, riding the lightning across the face of the Moon!”

On the Moon’s surface, rovers were already racing to retrieve the cargo pellet, spraying up rooster tails of dust behind them. And the crane was moving back into its position, ready for another run.

20: HUMAN RESOURCES

Eugene sat in his room, hands folded on a small table. The room was without decoration or personalization—minimal even by the standards of the Moon, where everything was filtered through the huge expense of being shipped up from Earth. He didn’t even have a closet, just the packing carton that must have brought his clothes to the Moon in the first place.

Eugene remained an enigma to Siobhan. He was a big, handsome boy. If you knocked him cold and rearranged his limbs a bit he’d have made a great fashion model. But his posture was slumped, his face creased up with concern and shyness. Siobhan thought she had never met anybody with a greater contrast between his inner and outer selves.

“So how are you feeling, Eugene?”

“Busy,” he snapped back. “Questions, questions, questions. It’s all I get, day and night.”

“But you understand why,” she said. “We’ve already started building the shield, and on Earth they are making other preparations. All on the basis of your predictions: it’s really quite a responsibility. And unfortunately, Eugene, right now it’s only you who can do that for us.” She forced a smile. “If you’re building a shield thirteen thousand kilometers across, a mistake in the sixth decimal place means a mismatch of a meter or more—”

“It gets in the way of the work,” he said.

She stopped herself from snapping back, I am the Astronomer Royal. I’ve done the odd bit of science myself. I do understand what it takes. But we’re talking about the safety of the world here. For God’s sake stop being such a prima donna… But she glimpsed real misery in his downcast face.

After all, she reflected, it wasn’t likely somebody as unworldly as this would be any use at prioritization or time management. Eugene surely had no mental equipment for handling conflicting demands—and probably no tact in dealing with those making such demands, from Prime Ministers and Presidents on down.

And then there was his public notoriety.

Siobhan had the feeling that even now, despite all the grave scientific pronouncements and political pontificating and arguing, most people didn’t really believe, in their guts, that the sunstorm was going to happen. Alvarez’s initial announcement had triggered a wave of alarm, flurries of speculation on the stock markets, flights into gold, and a sudden surge of interest in properties in Iceland, Greenland, the Falklands, and other extreme-latitude locations wrongly imagined to be relatively safe from the storm. But for most people, as the world kept turning and the sun kept shining, the sense of crisis quickly faded. Vast defensive programs, like the shield, were being mobilized, but even they weren’t visible yet to most people. It was still a phony war, the analysts said, and most people had forgotten about it and just got on with their lives. Even Siobhan found herself fretting about the long-term cosmological projects she’d been forced to abandon.

But in a world of billions there was a fraction of a percent imaginative enough, or crazy enough, to take the threat to heart—and a fraction of them looked for somebody to blame. As the man who had figured out the sunstorm, there were plenty prepared to dump their fear on Eugene. There had even been death threats. It had been a mercy he had stayed on the Moon, she thought, where his safety was relatively easy to assure. But even so he must have felt as if he were being flayed alive.

She got out her softscreen and began making notes. “Let me help you,” she said. “You need an office. A secretary…” She saw panic in his eyes. “Okay, not a secretary. But I’ll set up somebody to filter your calls for you. To report to me, not you.” But I think you will need somebody here on the Moon to hold your hand, she thought. An idea struck her. “How’s Mikhail?”

He shrugged. “Haven’t seen him.”

“I know he has his own priorities.” The Space Weather Service, which had suddenly grown from an obscure near joke to one of the most high-profile agencies in the solar system, was almost as inundated as Eugene himself. But she had seen Mikhail work with Eugene; she had a sense the solar astronomer would be able to get the best out of the boy. And, given the way Mikhail looked at Eugene, it would be a task Mikhail would perform with competence and affection. “I’ll ask him to spend more time with you. Maybe he could move back here to Clavius; he doesn’t have to be physically at the pole station.”

Eugene showed no notable enthusiasm for the idea. But he didn’t reject it outright, so Siobhan decided she had made some progress.

“What else?” She bent forward so she could see his face more clearly. “How are you feeling, Eugene? Is there anything you need? You must know how important your welfare is, to all of us.”

“Nothing.” He sounded sullen, even sulky.

“What you found is so important, Eugene. You could save billions of lives. They’ll build statues to you. And believe me, your work, especially your classic paper on the solar core, is going to be read forever.”

That provoked a weak smile. “I miss the farm,” he said suddenly.

The non sequitur took her aback. “The farm?”

“Selene. I understand why they had to clear it all out. But I miss it.” He had grown up in a rural area in Massachusetts, she remembered now. “I used to go work in there,” he said. “The doctor said I needed exercise. It was that or the treadmill.”

“But now the farm’s been shut down. How typical that in trying to save the world we kill off the one bit of green on the Moon!”

And how psychologically damaging that might be. In trying to figure out these spacebound folk she had read stories of cosmonauts on the first, crude, tin-can space stations, patiently growing little pea plants in experimental pots. They had loved those plants, those small living things sharing their shelter in the desolation of space. Now Eugene had shown the same impulse. He was human after all.

“I’ll fix it,” she said. “A farm’s out of the question for now. But how about a garden? I’m sure there’s room here in Hecate. And if there isn’t we’ll make room. You lunar folk need reminding of what you’re fighting to save.”

He looked up and met her gaze for the first time. “Thank you.” He glanced at the softscreen before him. “But if you don’t mind—”

“I know, I know. The work.” She pushed back her chair and stood up.

That night she went to Bud’s room.

He whispered, “I wasn’t sure if you’d come.”

She snorted. “I knew for sure you wouldn’t walk down the corridor.”

“Am I so transparent?”

“As long as the journey got made by one of us,” she said.

“I told you we’d be a good team.”

She unzipped her jumpsuit. “Prove it, hero.”

Their lovemaking was wonderful. Bud was a lot more athletic than she was used to, but he was more focused on her than most of her lovers ever had been.

And he was ingenious in his use of the Moon’s gentle gravity. “One-sixth G is the gravity of choice,” he gasped at one point. “On Earth you’re crushed. In zero G you’re floundering around like a beached salmon. In one-sixth, you’ve enough weight to give you a little traction, and yet you’re still as light as a kid’s balloon. Why, I’m told that even on Mars—”

“Shut up and get on with it,” she whispered.

Afterward she stayed awake for a long time, just relishing the strong warmth of his arms around her. Here they were, two humans in this bubble of light and air and warmth on the lethal surface of the Moon. Like the cosmonauts and their pea plants, she thought: all they had, in the end, was each other.

Even when the sun betrayed them, they had each other.

21: SHOWSTOPPERS

“So there it is,” Rose Delea said flatly. “You have two problems you can’t get over. Without the Chinese heavy-lift capability, you can’t finish the shield infrastructure on time. And even if you could, you don’t have a way to manufacture all the smartskin you need.” She sat back and stared out of her softscreen at Siobhan. “You’re fucked.”

Siobhan pressed the balls of her thumbs to her eyes, and tried to keep her temper. It was January 2039—six months after she had seen those first shield components stacking up on the Moon, already eighteen months since the June 9 event. Another Christmas had come and gone, a bleak and joyless festival, and little more than three years remained before the sunstorm was due to hit.

Save for Toby Pitt and the talking heads from space on the softscreens, Siobhan was alone here in the Royal Society Council Rooms, the location that had come to serve as her communications base. Toby’s job as the Society’s events manager had gradually evolved into his becoming her PA, amanuensis, and shoulder-to-cry-on. And she certainly felt like crying now.

“We’re fucked, Rose,” she said.

“What?”

“Rose, sometimes you sound like my plumber. You’re fucked is wrong. Language is crucial. It’s not my problem, it’s ours. We’re fucked.”

Bud Tooke, peering from another softscreen, laughed gently.

Rose glared. “Fucked is fucked, you stuck-up pom. I need a coffee.” And she pushed herself out of her chair and drifted out of shot.

“Here we go again,” Mikhail said grimly.

Despite her usual intrinsic anxiety about the schedule, before she had come into work this morning Siobhan had actually felt optimistic about the way things were going.

On the Moon, after months of stupendous effort by Bud and his people, the Sling was completed and operational. Even the construction of a second mass driver was under way. Not only that, but the glass manufacturing operations were proceeding apace: plants had been set up all over the bare soil of Clavius Crater, so that streams of components poured into the Sling’s launching bay by lunar day and night. Rose Delea, seconded from her helium-3 processing work, had proven a more than capable manager for that end of the project, despite her dour attitude.

Meanwhile Aurora 2 had been safely brought back from Mars and was lodged at L1, the crucial Lagrangian point suspended between Earth and sun. With the Sling fully operational the first loads of lunar-glass buttresses and struts had been fired up to the assembly site, and construction of the shield itself had started. Bud Tooke was now in nominal charge of all the subprojects at L1, and, as Siobhan had always known he would, he was delivering quietly and efficiently. Soon, it was said, the proto-shield would be big enough to see with the naked eye from Earth—or would have been, were it not forever lost in the glare of the sun.

Even Siobhan’s personal life had been looking up, to general astonishment among friends and family. She hadn’t expected that her affair with Bud would deepen so smoothly and so quickly, especially since they spent almost all their time on separate worlds. In the toughest days of her life, the relationship had been a source of comfort and strength to her.

But now, in what should have been a routine weekly progress meeting, two showstopper problems had come looming out of nowhere.

On her screen Rose Delea reappeared with coffee that sloshed in a languid low-G way. The conversation resumed, and Siobhan tried to focus on the issues.

Mathematically, the positioning of an object at a Lagrangian point was simple. If the shield had been a point mass, it could have been poised neatly on the sweeping line joining Earth to sun at L1. But this project was no longer mathematics; it was engineering.

For one thing the L1 point wasn’t really stable at all, but only semi-stable: if you knocked that point mass out of position it would tend to drift back to its place along the line of the Earth–sun radius, but would happily float away from the line in any other direction. So you needed to add station-keeping mechanisms, such as rocket thrusters, to hold the shield in place.

And then, of course, the shield was not a point mass, but an extended object large enough eventually to shadow the whole Earth. Only the shield’s geometric center, intersecting the Earth–sun line, could be properly balanced at the L1 point. All other points were drawn toward the center, and given time the shield would have crumpled in on itself. Making it rigid would have raised the mass unfeasibly. The problem was to be overcome by giving the shield a slow rotation. The spinning was stately, at only four revolutions per year—“as if God is twirling His parasol,” as Mikhail described it—but enough to keep the shield rigid.

But the rotation created other problems. Docking with a spinning object in space, even one as slow moving as the shield, was a lot more tricky than with a stationary object. More seriously, by being spun up, the shield would become a huge gyroscope. As it followed its orbit between Earth and sun it would tend to keep the same orientation in space—and so, over a year, it would tip its face away from the sun–Earth line, making it useless as a parasol.

Meanwhile there were other forces to consider besides gravity. Sunlight itself, a rain of photons, exerts a pressure on every object it touches. It is too gentle a force for human senses to detect on an upraised hand, but it would be enough to drive a yacht with filmy kilometer-wide sails from world to world—and it was certainly enough to exert a significant force on an object as large as the shield. There were other complications too, such as perturbation by the gravity fields of the Moon and the other planets, and a tweaking by Earth’s own magnetic field.

To cope with all this, the shield’s surface was to be made adjustable. Panels could be opened and closed in careful patterns, so that the gentle pressure of sunlight could be harnessed to turn the shield. It was an elegant solution: sunlight itself would be used to keep the shield properly positioned.

But to maintain its station in this environment of multiple and constantly changing forces, the shield itself had to be smart enough to be aware of its position in space, and able to adjust itself dynamically. Ideally every square centimeter of the shield would know all about the forces acting on it and on the shield as a whole, and would be able to compute how it should position itself in response.

This distributed, interconnected intelligence was to be achieved by the manufacture of a “smartskin.” The shield’s epidermis, less than a micrometer thick, would not just be a reflective skin but would be packed with circuitry. The local smartness, interconnected, would of course add up to a total powerful intelligence. The completed shield would, it was thought, be the smartest single entity humankind had yet constructed—smarter even, probably, than Aristotle, the only uncertainty coming because nobody knew quite how smart Aristotle was.

So much for the design, complicated enough in itself. The implementation was something else.

The manufacture of the smartskin was one headache today; there weren’t enough nano-factories to turn it out in time. But even more serious was the problem caused by the pressure of sunlight. Although it could be used for active position control, its very existence caused a fundamental difficulty—which was the day’s second showstopper.

“Let’s go through it step by step,” Bud said. “The sunlight presses on the reflective face of the mirror. The light pressure acts against the sun’s gravity—so it’s as if the sun’s gravity is effectively reduced, and the L1 balance point is moved toward the sun along the Earth–sun line.

“Now, we’re trying to minimize the shield’s design mass. But the lighter the shield is, the more the sunlight can push it back. And the farther it drifts toward the sun, the bigger the shield has to be to shade the whole Earth. So its mass actually starts increasing again… These two effects counteract to provide a minimum solution. Am I right? For a given thickness of film there is a theoretical minimum mass for the shield, below which there is no feasible design solution.”

Siobhan said, “And without the Chinese—”

“We can’t meet that minimum,” Rose said with a kind of grim pleasure.

The problem was a shortfall of heavy-lift capacity. Although the Chinese government had initially declined to participate in the shield program, Miriam Grec had been sure that after enough emollient diplomacy, and a little horse trading, the Chinese would come on board. Miriam had actually instructed Siobhan to factor into her plans the availability of the Chinese fleet of Long March heavy-lift boosters.

Well, Miriam Grec had proven to be right about many things, but not about the Chinese. Their resistance to participation had not altered one jot, and their space launch capabilities were being dedicated, it seemed, to some secretive scheme of their own.

Whatever the Chinese were up to didn’t matter to Siobhan. All she did care about was that despite months of frantic redesign they had failed to come up with a feasible solution: without the Chinese and their Long March boosters—and maybe even with them, said the pessimists—there just wasn’t any way to get that minimum mass to L1 in time.

Siobhan knew that momentum was everything for this project. The shield was hugely, horribly, ruinously expensive: the project absorbed more than the net GDP of the United States, and therefore a respectable fraction of the whole world’s economic output. Indeed the shield was thought to be humankind’s single most expensive project in real terms since the “project” of winning the Second World War. The money didn’t come out of nowhere, and many other programs, notably climate-change mitigation efforts in the desiccated heart of Asia and drowning Polynesia, were being put on hold, to predictable protests.

As the project became more real, it was provoking sincere political anger. In a way Siobhan welcomed that; it meant that more than a year after Alvarez’s Christmas announcement, the “phony war” was coming to an end, and people were starting to believe enough in the sunstorm to care what was being done about it. Of course there were technical problems to solve; what they were attempting had never been done before. But Siobhan knew that if she allowed a hint of doubt to seep out of her management structure, it would soon erode the fragile political consensus behind the project—an infrastructure every bit as essential to the shield as the glass struts and booms being shipped up from the Moon.

Siobhan massaged her temples. “So we find another way to do it. What can we change?”

Rose ticked points off on her strong fingers. “You can’t change the basic forces involved. You can’t change the gravity fields of sun or Earth, or the pressure per square centimeter of sunlight. You can’t shrink the shield. If it was transparent, sunlight would pass straight through the shield without troubling it, of course.” She smiled. “But then there would be no point in building it in the first place, would there?”

“There must be something, damn it,” Siobhan snapped.

She looked around at the softscreens that lined the walls of the room. The faces that peered back at her, her senior project managers, were projected from various corners of the Earth, the Moon, and L1 itself. The expressions of Bud and Mikhail Martynov as always radiated sympathy and support. Rose was wearing her usual it-can’t-be-done scowl. Many of the others were more reserved. Some may actually have been grateful to Rose and her showstoppers, as she gave them something to hide their own issues behind.

They just didn’t get it, Siobhan thought. There was a failure of imagination, even among her people, some of the smartest engineers and technologists around, who were closer to the project than anybody else. They weren’t just building a bridge here, or just flying to Mars; this wasn’t just another project, another line on a curriculum vitae. This was the future of humanity they were dealing with. If they fouled up, whatever the cause, there would be no tomorrow in which to hand out blame: there would be no careers to wreck, no new directions to seek. Siobhan ought to welcome Rose’s bluntness, she thought; at least from her you got the straight skinny, whatever the consequences.

“I’m not going to give you a pep talk,” she said. “Let me just remind you what President Alvarez said. Failure is not an option. It still isn’t. We are going to work on this until our foreheads bleed, and we are going to find solutions to both these problems of ours today, come what may.”

Bud murmured, “We’re with you, Siobhan.”

“I hope that’s true.” She stood, pushing back her chair. She said to Toby, “I need a break.”

“I don’t blame you. Just a reminder—your ten o’clock is outside.”

Siobhan glanced at a softscreen diary page. “Lieutenant Dutt?” The soldier who had, it seemed, spent more than a year trying to get access to Siobhan, with grave news she wouldn’t divulge to anybody else, and had finally drifted to the top of the in-tray. More problems. But at least different problems.

She stretched, trying to dissipate the ache in her upper neck. “If anybody cares I’ll be back in thirty minutes.”

22: TURNING POINT

Lieutenant Bisesa Dutt, British Army, was waiting for Siobhan in the City of London Rooms. She was drinking coffee and studying her phone.

As Siobhan crossed the room she was distracted by a peculiar shadow. Looking out the window, she glimpsed a gaunt framework rising beyond the rooftops of London: it was the skeleton of what would become the London Dome, the city’s own effort to protect itself from the sunstorm. It was already the mightiest construction project in London’s long history, although predictably it was dwarfed by still mightier shelters being raised over New York, Dallas, and Los Angeles.

From the beginning they had always known, just as Alvarez had announced, that the shield was not going to save the Earth from one hundred percent of the sun’s rage, even assuming it got built at all. Some of it was going to get through—but the shield would give humanity a fighting chance, a chance that had to be taken. The trouble was that nobody knew how much pain the world below, and cities like London, would have to absorb.

The Dome was merely the most visible of the changes befalling the city. Across London the government had begun a program of laying up stores of nonperishable food, fuel, medical supplies, and the like, and the prices of such items were escalating. Even water rates were increasing as the authorities siphoned off supplies to fill immense underground tanks under the city’s parks. It was like preparing for war, Siobhan thought. But the necessity was very real.

Certainly the building of the Dome, a physical manifestation of the danger to come, had started at last to make people believe, deep in their guts, that the sunstorm was real. Across the city there was a sense of apprehension, and the medical services reported upsurges in anxiety and stress. But there was excitement too, in a way, even anticipation.

Siobhan had been traveling extensively, and she’d found that things were much the same everywhere.

In the United States especially she thought there was a sense of determination, of unity; America, as always, was having to bear a disproportionately heavy weight of the global effort. Across the nation, even where domes were impractical, there was a neighborhood-level drive to prepare, as the National Guard, the Scouts, and a hundred volunteer drives dug shelters into their own backyards and their neighbors‘, filled underground tanks with rainwater, and collected aluminum cans to be filled up with emergency rations. Meanwhile there was a less obvious but equally dramatic effort to archive as much knowledge as possible, in digital and hardcopy forms, in great storage facilities in deep mine shafts, wells, Cold War–era bunkers, and even on the Moon. This was after all the true treasure of the nation, indeed of humankind—but this program gathered more controversy from those who argued that you should save “people first and last.” President Alvarez was proving expert once more in guiding her nation’s spirits; she was planning a program of celebrations of World War II centenary events, leading up to Pearl Harbor in 2041, to remind her fellow citizens of great trials they had faced before, and overcome.

There was dissension, all over the world. Aside from genuine differences of opinion about how to respond to this emergency, there were plenty of devout types who thought it was all a punishment by God, for one crime or another—and others who were angry at a God who had allowed this to happen. And some, the radical green types, said humankind should just accept its fate. This was a kind of karmic punishment for the way we had messed up the planet: let the Earth be wiped clean, and start again. Which might be a comforting idea, Siobhan thought grimly, if you could be sure there would be anything left after the sunstorm to start again with.

But even so there was still an unreal sheen to things. With the sun shining brightly over London, the Dome seemed as inappropriate as a Christmas tree in July. Most people just got on with their lives—even those who thought it was all a scam by the construction companies.

And in the middle of all this, here was Lieutenant Bisesa Dutt, and another mystery for Siobhan.

She reached Bisesa’s table and sat down, asking an attendant for coffee.

“Thank you for seeing me,” Bisesa began. “I know how busy you must be.”

“I doubt if you do,” Siobhan said ruefully.

“But,” Bisesa said calmly, “I think you’re the right person to hear what I have to say.”

As she sipped her coffee Siobhan tried to get a sense of Bisesa. As Astronomer Royal she had always been expected to deal with people—sometimes thousands of them at once, when she gave public lectures. But since being press-ganged by Miriam Grec into this position of extraordinary responsibility, as a sort of general manager of the shield project, she believed she was acquiring a protective skill in sizing people up: the quicker you understood what faced you, the better you could deal with it.

And so here was Bisesa Dutt, Army officer, out of uniform, far from her posting. She was of Indian extraction. Her face was symmetrical, her nose long, and her gaze was strong but troubled. She was above medium height, with the physical confidence of a soldier. But she was gaunt, Siobhan thought, as if she had been hungry in the past.

Siobhan said, “Tell me why I need to listen to you.”

“I know the date of the sunstorm. The exact date.”

Because the authorities, guided by teams of psychologists, were continuing to work to minimize panic, that was still a closely guarded secret. “Bisesa, if there has been a security leak, it’s your duty to tell me about it.”

Bisesa shook her head. “No leak. You can check.” She lifted one foot and tapped the sole with her fingernail. “I’m tagged. The Army has been monitoring me since I turned myself in.”

“You went AWOL?”

“No,” Bisesa said patiently. “They thought I had. Now I’m on compassionate leave, as they call it. But they are monitoring me anyhow.”

“And so the date—”

“April 20, 2042, you mean?”

Siobhan regarded her. “Okay, I’ll bite. How do you know that?”

“Because there is a solar eclipse on that day.”

Siobhan raised her eyebrows. She murmured, “Aristotle?”

“She’s correct, Siobhan,” Aristotle whispered in her ear.

“Okay. But so what? An eclipse is just a lining up of sun, Moon and Earth. It has nothing to do with the sunstorm.”

“But it does,” Bisesa said. “I was shown an eclipse, during my journey back home.”

“Your journey.” Siobhan had only glanced at Bisesa’s file. She’d come down to meet her on impulse, to get away from her teleconference for a while. Now she was beginning to regret it. “I know something of the story. You had some kind of vision—”

“Not a vision. I don’t want to use up our time discussing it. You have the files; if you believe me, you will check up on it later. Right now I need you to listen. I knew that something dreadful was going to happen to the Earth, the day I got back. And by showing me the eclipse they were telling me it had something to do with the sun.”

“They?…”

Bisesa’s face clouded, as if she didn’t quite believe it all herself—and she rather wished she didn’t have to. But she plowed on.“Professor McGorran, I believe that the sunstorm is no accident. I believe it is the result of intentional harm being done to us by an alien power.”

Siobhan pointedly glanced at her watch. “What alien power?”

“The Firstborn. That’s what we called them.”

“We?… Never mind. I don’t suppose you have any proof.”

“No—and I know what you’re thinking. People like me never do.”

Siobhan allowed herself a smile, for she had been thinking exactly that.

“But the Army did find some anomalies in my physical condition they couldn’t explain. That’s why they gave me leave. That’s proof of a sort. And then there’s the principle of mediocrity.”

That threw Siobhan. “Mediocrity?”

“I’m no scientist, but isn’t that what you call it? Copernicus’s principle. There should be nothing special about any given location in space or time. And if you have a chain of logic that indicates there is something special about a given moment—”

“Never trust coincidences,” Siobhan said.

Bisesa leaned forward intently. “Doesn’t it strike you that the sunstorm, occurring now, is the mightiest coincidence of all time? Think about it. Humanity is a mere hundred thousand years old. The Earth, and the sun, are forty thousand times as old as that. If it were purely natural, surely the sunstorm could have occurred at any time in Earth’s history. Why should the sun blow its top now, just in this brief moment when there happens to be an intelligence running around on the planet?”

For the first time in the course of the conversation Siobhan felt faintly disturbed. After all, she’d had, independently, vague thoughts along these lines. “You’re saying this is no accident.”

“I’m saying the sunstorm is intentional. I’m saying we are the target.” Bisesa left the word hanging in the air.

Siobhan turned away from the intensity of her gaze. “But this is all just philosophy. You have no actual proof.”

Bisesa said firmly, “But I believe that if you look for proof you will find it. That’s what I’m asking you to do. You’re close to the scientists who are studying the sunstorm. You could make it happen. It could be vital.”

“Vital?”

“For the future of humankind. Because if we don’t understand what we’re dealing with, how can we beat it?”

Siobhan studied this intent woman. There was something odd about her—something of another world, perhaps, another place. But she had an intelligent soldier’s clarity and conviction. She could be wrong in what she says, Siobhan thought. But I don’t think she’s mad.

On a whim she dug into her jacket pocket and dug out a scrap of material. “Let me show you what we’re actually working on right now, the problems I’m wrestling with. Have you ever heard of smartskin?…”

This was a prototype sample of the material that would some day, if all went well, be stretched over the gaunt lunar-glass framework of the shield. It was a glass-fiber spiderweb, complex and full of components, detailed on scales as small as the eye could see. “It contains superconducting wires to transmit power and to serve as comms links. Diamond fibers, too small to see, for structural strength. Sensors, force multipliers, computer chips, even a couple of tiny rocket motors. There, can you see?” The scrap, the size of a pocket handkerchief, weighed almost nothing; the little rocket motors were like pinheads.

“Wow,” Bisesa said. “I thought it was just a big dumb mirror.”

Siobhan shook her head ruefully. “That would be too easy, wouldn’t it? The whole shield won’t have to be smart fabric, but maybe one percent of it will. It’s like a huge cooperative organism.”

Bisesa touched the material reverently. “So what’s the problem?”

“The manufacture of the smartskin. The trouble is, it has to be nanotechnological…”

Nanotechnologies were still in their infancy. But nanotech, a process that built atom by atom, was the only way to manufacture a material like this, with a complexity that went down below the molecular.

Bisesa smiled. “Can I tell my daughter about this? She’s a modern sort of kid. Nanotech fairy tales are her favorite sort.”

Siobhan sighed. “That’s the trouble. In a story you throw in a handful of magic dust, and nano will build you anything—right? Well, nano will build almost anything, but it needs something to build with, and energy to do it. Nano is more like biology, in some ways. Like a plant, a nano application draws energy and materials from its environment, and uses them to fuel its metabolism, and build itself up.”

“Instead of leaves and trunks, space shields.”

“Yes. In nature metabolic processes are slow. I once saw a bamboo shoot growing at naked-eye speeds: nano is directed, and faster than that. But not much faster.”

Bisesa stroked the bit of smartskin. “So this stuff grows slowly.”

“Too slowly. There aren’t enough factories on the planet for us to churn out the quantity of smartskin we need. We’re stuck.”

“Then ask for help.”

Siobhan was puzzled. “Help?”

“You know, people always think on a big scale—what can the government do for me, how can I gear up industry to churn out what I want? But I learned, working for the UN, that the way the world really works is through ordinary people helping each other, and helping themselves.”

“What are you suggesting?”

Bisesa cautiously picked up the smartskin. “You say this stuff grows like a plant. Well, could I grow it?”

“What?”

“I’m serious. If I put it in my window box, and fed and watered it, and kept it in the sun—”

Siobhan opened her mouth, and closed it. “I don’t know. An open plant pot wouldn’t do, I’m sure of that. But maybe some reasonably uncomplicated kit would work. And maybe the design could be adapted to draw on local nutrients—”

“What does that mean?”

“From the soil. Or even household waste.”

“How would you get it started?”

Siobhan thought. “You’d need some kind of seed, I guess. Enough to encode the construction data, and to bootstrap the macro-scale growth.”

“But if my neighbor grew one, she could pass on seeds to me. And I could pass them on from my, umm, ‘plant’ to the next person.”

“And then you’d need some kind of collection system to bring the finished smartskin to some central point… But wait,” Siobhan said, thinking fast. “The total area of the shield is around a hundred thousand billion square meters. One percent of that, and a global population of ten billion—why, every man, woman, and child on Earth would have to produce, oh, say a blanket ten or twenty meters on a side. Everybody.”

Bisesa grinned. “Surely less than that if the factories do their job. And it isn’t so much. We’ve still got three years. You’d be surprised what Boy Scouts and Girl Guides can produce when they’ve a mind to do it.”

Siobhan shook her head. “This needs thinking through. But if it’s possible I’ll owe you a debt of gratitude.”

Bisesa seemed embarrassed. “It’s an obvious idea. If I hadn’t come up with it, you would have yourself—or somebody else.”

“Maybe.” She smiled. “I ought to introduce you to my daughter.” Saving the world is so 1990s disaster movie! Nobody believes in heroes anymore, Mum… This way, everybody would be a hero, she supposed. Maybe it would catch even Perdita’s imagination.

Bisesa asked, “Why did you show me this stuff?”

Siobhan sighed. “Because this is real. This is engineering. This is what we’re building, right now. I thought if you saw this—”

“It might puncture my fantasies,” Bisesa said.

“Something like that, maybe.”

“Just because something is big, indeed superhuman, doesn’t make it any less real,” Bisesa said evenly. “Or any less relevant. And anyhow, as I’ve said, you don’t have to believe me. Just look for proof.”

Siobhan stood up. “I really ought to get back to my meeting.” But she hesitated, intrigued despite herself. “You know, I’m open-minded enough to accept the existence of extraterrestrial aliens as a possibility. But what you’re describing makes no psychological sense. Why would these hypothetical Firstborn try to destroy us? And even if it were so, why would they give you these hints and glimpses? Why would they warn any of us—and why you?…”

But even as she spoke, Siobhan thought of a possible answer to her objection.

Because there are factions among these Firstborn. Because they are no more united and uniform of view than humanity is—why should a more advanced intelligence be homogeneous? And because there are some of them, at least, who believe that what is being done is wrong. A faction of them, working through this woman, Bisesa, are trying to warn us.

This woman could be crazy, Siobhan thought. Even after meeting her, she was ninety percent sure that was true. But her story did make a certain sense. And what if she was right? What if an investigation did turn up evidence to back her claims? What then?

Bisesa was watching her, as if reading her thoughts. Siobhan didn’t trust herself to speak again, and she hurried away.

When she got back to the Council Room, the level of chatter among the population of heads dropped a little. She stood in the middle of the room and peered around. “You’re all acting as if you’ve got something to be ashamed of.”

Bud said, “Perhaps we have, Siobhan. It’s beginning to look as if things aren’t as black as we painted them. The issue of the solar pressure and positioning—one of us came up with a solution. We think.”

“Who?” Siobhan faced Rose Delea. “Rose. Surely not you.”

Rose actually looked embarrassed. “Actually it was our conversation earlier. When I said something about how we’d have no problem if the sunlight was allowed to pass straight through the shield? It got me thinking. There is a way we could make our shield transparent. We don’t reflect the sunlight. We deflect it…”

The shield would be made clear, but scored on one side with fine parallel grooves: prisms.

“Ah,” Siobhan said. “And each ray of sunlight would be turned aside. We’d be building, not a mirror, but a lens, a huge Fresnel lens.”

It would be an all-but-transparent lens that could turn the sunlight away a little, by only a degree or less. But that would be sufficient to spare the Earth from the blast of the sunstorm. And a lens would suffer only a fraction of the photon pressure of a fully reflective mirror.

Rose said, “It’s really no more of a manufacturing challenge than our current design. But the total mass could be much less.”

“And so we’re back in the realms of feasible design solutions?” Siobhan asked.

“With a vengeance,” Bud said, beaming.

Siobhan glanced around. Now she saw restlessness in their expressions, even eagerness; they were all keen to get back to their people, to begin exploring this new idea. It was a good team, she thought with pride, the best there was, and she could trust them to take this new idea and worry it until it was thoroughly integrated into the design and the construction program—by which time the next obstacle would have appeared, and they would all be back here again.

“Another bit of good news before we close,” she said. “I may have a solution to the nanotech manufacturing problem too.”

Eyes widened.

She smiled. “It will keep. I’ll mail you the details when it’s fleshed out a bit more. Thank you, everybody. Meeting closed.”

The screens winked out, one by one.

“You old ham,” Toby grinned.

“Always leave them wanting more.”

“Were you serious about the smartskin issue?”

“Needs work, but I think so.”

“You know,” Toby said, “mathematically speaking L1 is a turning point—a point where a curve changes direction, from downhill to up. That’s why it’s a point of equilibrium.”

“I know that—ah. You think we’ve gone through a turning point on the project today?”

“What do you think?”

“I think you should leave the headlines to the journalists. Okay. What’s next?”

23: HEATHROW

In March 2040—with another dismal Christmas come and gone, and just a little over two years left before sunstorm day—Miriam Grec decided to visit the shield construction site in person. And that meant flying into space, for the first time in her life.

As she was driven away from the Euro-needle that day she felt guilty but excited, like a child playing hooky from school. But she needed a holiday; her friends and enemies alike would agree on that, she thought wryly.

London’s Heathrow had been an airport for a century, and now it was a spaceport too. And, sitting on a long, hardened runway in the watery sunlight, the spaceplane looked quite remarkably beautiful, Miriam thought.

The Boudicca was a slim needle some sixty meters long. It had alarmingly small vanes at its nose and tail, and even its main wings were just stubby swept-back deltas. Mounted on the wingtips were fat, asymmetrical nacelles that contained the principal rocket motors—or rather they would work as rockets in the vacuum of space, but in Earth’s atmosphere they breathed air like jet engines. The plane’s upper surface was a dull white ceramic shell, but its underside was coated with a gleaming black plate, a heat shield for reentry, made of a substance that was a remote descendant of the thermal tiling that had given the venerable space shuttle so much trouble.

Despite the ground support vehicles that clustered around it and the clouds of vapor steaming from its tanks of cryogenic fuel, the plane really did look as if it belonged to another order of creation entirely, and had only diffidently set down here on Earth. But it was a working ship—indeed, a veteran of space. That gleaming outer hull was punctured with the nozzles of attitude control rockets around which the surface was scarred and blistered, and repeated reentries had splashed scorch marks over its underside.

And the plane was proudly British. While the tailplane bore on one side the starry circle of the Eurasian Union, on the other side waved an animated Union flag, and on the spaceplane’s wings and flank were painted the famous roundels of the Royal Air Force, a reminder that this soaring bird of space could be called on to serve military duties.

The design had an ancestry dating back to pioneering studies in the 1980s by firms like British Aerospace and Rolls-Royce, paper birds with names like Hotol and Skylon. But those studies had languished until the 2020s, when a new breed of materials technologies and engine designs, and the new push into space, had suddenly made a fleet of fully reusable spaceplanes a commercial proposition. And when the planes actually flew, of course, the British were quite unreasonably proud of their beautiful new toys.

The choice of a female name was obviously right, Miriam thought: surely this spaceplane was the most beautiful piece of British aeronautical engineering since the Spitfire. But the name of the Celtic queen who had once defied the Romans, selected by a popular vote, seemed a rather tactless moniker in these days of pan-Eurasian harmony—though Miriam wondered if the second choice would have been any more acceptable: Margaret Thatcher…

Still, even in these days of a united Eurasia you had to respect lingering national sentiments, as long as they played themselves out in a constructive way. And besides, as Nicolaus never ceased to remind her, this year, 2040, was an election year. So Miriam allowed herself to be photographed before the shining hull, a smile fixed to her face.

She rode a small escalator, and entered the plane through a hatch cut in the curving fuselage.

She found herself in a poky little compartment. If she had expected an elegance inside the plane to match its beautiful exterior, she was immediately disappointed. There were a dozen seats set in unimaginative rows, rather like first-class seats on a long-haul flight—but no better than that. There weren’t even windows in the walls.

She was greeted by a tall, very upright man in a Eurasian Airways uniform and a peaked cap. His hair was silver-white, and he must have been in his late seventies; but he had sharp, good-looking features, his blue eyes were clear, and when he spoke his accent was a reassuring upper crust. “Madam Prime Minister, I’m delighted to welcome you aboard. I’m Captain John Purcell, and it’s my pleasant duty to make sure you enjoy your flight up to the shield. Please take a seat; the flight is yours today, and you can take your pick…”

Miriam and Nicolaus sat one row apart, so they had the luxury of more room. Purcell helped them strap into intimidatingly robust harnesses, then offered them drinks. Miriam accepted a Bucks Fizz. What the hell, she thought.

Nicolaus declined a drink, a bit testily. It struck Miriam that he had seemed edgy for some time. She supposed that anybody had a right to be nervous about being hurled into space, even nowadays. But perhaps there was more to it than that. She remembered her resolve to try to get him to open up a bit more.

Now Nicolaus called over his shoulder, “You know, this reminds me of the Concorde. The same mix of a high-tech exterior, but a poky little passenger cabin.”

Purcell perked up. “Did you ever fly the old plane, sir?”

“No, no,” Nicolaus said. “I just crawled around a retired model in a museum a few years ago.”

“Was that the one at RAF Duxford?… As it happens, I used to fly the Concorde, before she was retired at the turn of the century. I was a pilot for the old British Airways.” He grinned at Miriam, almost flirtatiously, and smoothed back his silver hair. “I’m sure you can tell I’m old enough. But the spaceplane is a different bird altogether. It is human-rated, of course, but it was primarily designed as a cargo carrier. Actually it’s almost all propellant.”

Miriam said, a bit nervously, “It is?”

“Oh, yes. Of three hundred tonnes all-up weight, only twenty tonnes is payload. And we’ll use up almost all of that fuel getting away from the Earth.” He eyed her cautiously. “Madam, I’m sure you were sent a briefing pack. You do understand that we will glide home from space, without powered engines? Returning to Earth is a question of shedding energy, not spending it…”

She’d had no time to touch the glossy briefing pack, of course, but she did know that much.

“So we’re just a flying bomb,” Nicolaus said.

Even allowing for his nervousness Miriam was surprised he would say such a thing.

Purcell’s eyes narrowed a bit. “I like to think we’re a bit smarter than that, sir. Now if I may I will take you through our emergency procedures…”

These turned out to be rather alarming too. One option, in the event of decompression, involved being zipped up into a pressurized bag, as helpless as a hamster in a plastic globe. The idea was that astronauts in spacesuits would manhandle you inside your sphere across to a rescue ship.

Captain Purcell smiled, competent, reassuring. “Madam Prime Minister, we no longer treat our passengers as children. Everything has been done to ensure your safety, of course. I could talk you through the flight profile, and describe to you how our engineers have labored to close what they unromantically call ‘windows of nonsurvivability.’ But this spaceplane is still a young technology. One has to simply ‘buy the risk,’ as we used to say in my day—and sit back and enjoy the ride.”

The ground preparations appeared to be complete. Large, high-resolution softscreens unrolled over the walls and ceiling like blinds, and lit up with daylight. Suddenly it was as if Miriam were sitting in an open framework, looking out at the runway’s long perspective.

Purcell began to strap himself into a seat. “Please enjoy the view—or, if you prefer, we can blank out the screens.”

Miriam said, “Shouldn’t you be up in the cockpit?”

Purcell looked regretful. “What cockpit? Times have changed, I’m afraid, madam. I’m the Captain on this flight. But Boudicca flies herself.”

It was all a question of economy and reliability; automated control systems were much simpler to install and maintain than a human pilot. It just defied human instinct, Miriam thought, to give up so much control to a machine.

And then, quite suddenly, it was time to leave. The plane shuddered as the big wing-mounted engines lit up—an invisible hand pushed Miriam back into her seat—and Boudicca was hurled like a spear down the long runway.

“Don’t worry,” Purcell called over the engine noise. “The acceleration will be no worse than a roller coaster. That’s why they keep me on, I think. If an old duffer like me can live through this, you’ll be fine!—”

Without ceremony Boudicca tipped up and threw herself into the sky.

London’s sprawl opened up beneath Miriam.

Orienting herself by the shining chrome band of the river, she picked out Westminster at its sharp bend in the river’s flow, said to be the place where Julius Caesar had first crossed the Thames. As her viewpoint rose higher the urban carpet of Greater London spread out below her, kilometer upon kilometer of houses and factories, a floor of concrete and tarmac and brick. In the spring morning light the suburban avenues were like flower beds, Miriam thought, stocked with brick-red blooms that gleamed in the sun. You could see the streets gather into little knots, relics of villages and farms planted as far back as the Saxons, now submerged by the urban sprawl. Miriam had grown up in the French countryside, and despite her career path was averse to city life. But London from the air really was remarkably beautiful, she thought—accidentally, for nobody had planned it this way, and yet it was so.

As she climbed farther she saw that over the heart of the metropolis the great Dome was rising, skeletal and tremendous, designed to protect all those layers of history. She was glad it was there, for she felt a surging affection for the scattered, helpless city that lay spread-eagled below her, and a sense of duty to protect it from what was to come.

Soon London was lost in cloud and haze. When she looked ahead, the sky was fading from deep blue, to purple, and at last to black.

24: BDO

Shining in the light that flooded space, Aurora 2 was undeniably a magnificent sight. But it was a complicated, ungainly magnificence, Miriam thought. Unlike Boudicca this ship had never been intended to fly in the atmosphere of any world, not even Mars, and so had none of the spaceplane’s slender aerodynamic grace.

Aurora looked something like a drum majorette’s baton. The spine of the ship was a slim triangular spar some two hundred meters long. Under thrust, the greatest load the Aurora had to bear was along the length of its spine—and that was the direction in which this fragile ship was strongest, reinforced with struts of nano-engineered artificial diamond. At one end of the spine clustered power generators, including a small nuclear fusion reactor, and an ion-drive rocket engine whose gentle but relentless acceleration had pushed Aurora all the way to Mars and back. Spherical fuel tanks, antennae, and solar-cell arrays were strung along the spine. At the spine’s other end was a bloated dome that contained the crew quarters: habitable compartments, a bridge, life support systems. Somewhere in there, surrounded by water tanks for extra shielding, was the small, cramped, thick-walled solar-storm shelter where the crew, caught in interplanetary space, had retreated during the blistering hours of June 9, 2037.

And the shield that would save the world was already growing around the Aurora, its glistening surface spiraling out like a spiderweb.

Aurora served as a construction shack for the crews who, ferried up from Earth and Moon, labored to complete this mighty project. It was a noble destiny for any ship, Miriam thought. But Aurora had been destined to orbit another world, and there was something poignant about seeing it meshed up in a tangle of scaffolding. Miriam wondered if the ship’s own artificial intelligences, thwarted of their true purpose, knew some ghost of regret.

Boudicca docked with the Aurora‘s habitable compartment, nestling belly-first against its curving hull like a moth settling on an orange.

Miriam and Nicolaus were met by an astronaut: Colonel Burton Tooke. Bud wore coveralls, practical enough but freshly laundered and pressed, and adorned with astronaut wings, mission logos, and military decorations. Bud extended a hand and helped pull Miriam through the docking tunnel. “You seem to be coping fine with the lack of gravity,” he offered.

“Oh, I took some spins around the Boudicca‘s cabin. It was great fun—after the first twelve hours or so.”

“I can imagine. Space sickness hits most of us. And most people get through it.”

Nicolaus hadn’t, however, a fact that had given Miriam some rather unkind satisfaction. Just for once, in that bubble of metal drifting between worlds, it had been she who had had to look out for him.

Miriam had spent most of the flight working; she was reasonably up to date, and even felt quite rested. So she left Captain Purcell to sort out her few bits of luggage, and accepted Bud’s invitation for a quick tour. Nicolaus followed, cameras sitting on his scalp and shoulder like glistening birds, determined not to miss a moment of this photo opportunity.

They drifted through the cramped corridors of the Aurora. This was a ship designed for space; there were pipes, ducts, and removable panels on walls, ceiling, and floor, rails and rungs to help you pull your way along in zero G, and a color-coding in pastel shades to help you remember which way was up. It was difficult to grasp that this unremarkable working space had sailed across the solar system, all the way to Mars and back.

Despite the efficiency of the recycling systems there was a powerful, almost leonine stink of people. But they met nobody; the crew were either avoiding the visiting brass, or, much more likely, were out working somewhere. It was all very different from her usual Prime Ministerial visits, and oddly intimate—and she certainly didn’t miss the usual scrum of journalists and assorted hangers-on.

They reached the hatchway to Aurora‘s observation deck. Bud pushed open the door, and sunlight flooded over Miriam’s face. The deck’s “picture window” turned out to be a pane of toughened Perspex a lot smaller than any of the windows in her office in the Euro-needle. But once, briefly, this window had looked down over the red canyons of Mars—and now it looked out into space.

There was work going on out there. A framework of open struts jutted out from just below the window, and extending far into the distance. Astronauts in color-coded spacesuits were crawling all over, pulling themselves along with handholds or cables or pushed by small thruster packs on their backs. There must have been a hundred people in that first glance, and as many autonomous, multilimbed machines, moving through a sunlit three-dimensional maze of scaffolding. It was hugely impressive, but complex, baffling.

“Tell me what they’re doing.”

“Okay.” Bud pointed. “In the distance, you can see heavy-duty equipment moving those struts into place.”

“Those look like glass. The shield’s framework?”

“Yeah. Moon glass. We’re extending the structure in a spiral fashion around the Aurora, so that at any given moment we keep the center of gravity of the whole BDO right here at L1.”

She asked, “ ‘BDO’?”

Bud looked abashed. “The shield. We astronauts will have our acronyms.”

“And it stands for—”

“Big Dumb Object. Kind of an in-joke.”

Nicolaus rolled his eyes.

Bud said, “The struts are prefabricated on the Moon. But up here we’re manufacturing the skin itself—not the smart stuff coming from Earth; just the simple prismatic film that we’ll lay over most of the BDO’s area.”

He pointed to an astronaut wrestling with an ungainly piece of equipment. It looked as if she were extracting a huge balloon animal from a packing case. It was an almost comical sight, but Miriam took care to keep her face straight.

Bud said, “We use inflatable Mylar formers as molds. Designing the inflatable itself is an art. You have to figure the deployment dynamics. When you blow it up you don’t want it stretching out of shape; the Mylar is only as thick as freezer film. So we simulate backward, letting it deflate its way into the box, trying to make sure it will deploy smoothly without tangling itself up or stretching…”

She let him talk on. Bud was obviously proud of the work being performed here, meeting the challenges of an environment where the simplest task, such as blowing up a balloon, was full of unknowns. And anyhow, some space-buff piece of her was enjoying his talk of “deployment dynamics” and the rest.

“And when the mold is ready,” he was saying, pointing to another area of work, “we spray on the film.”

An astronaut supervised a clumsy-looking robot that rolled along a boom stretched out before a big inflatable disk. The robot was using a roller to smear a glassy surface on the Mylar face of the disk. The robot, working calmly, looked as if it were doing nothing more exotic than painting a wall.

“The Mylar comes up from the ground in solid blocks,” Bud said. “To make a film, you heat the stuff and force it out through hot nozzles, so you get jets of filament. You give this stuff a positive charge, and make the target surface a negative electrode, so the polymer filament is drawn out like taffy, becoming hundreds of times thinner in the process. You couldn’t do this on Earth; gravity would mess with everything. But here you just squirt it on, deflate the mold, and peel it off.”

“I want one of those robots to paint my flat.”

He laughed, but it was a bit forced, and she was painfully aware that everybody who came here must make a similar joke.

He said, “The robots and machines and processes are all very well. But the heart of this place is the people.” He glanced at her. “I come from a farming area in Iowa. As a kid I always liked to read stories of blue-collar guys just like my father and his buddies working in space, or on the Moon. Well, it can’t be that way, not for a long time. This is still space, a lethal environment, and the work we’re doing is highly skilled engineering. None of those grease monkeys out there is less qualified than a Ph.D. Blue collar they ain’t, I guess. But they have the heart—you know what I’m saying? They’re working twenty-four seven to get this job done, and some of them have been up here for years already. And without that heart none of this would get done, for all our gadgets.”

“I understand,” she said softly. “Colonel, I’m impressed. And reassured.”

So she was. Siobhan had briefed her well on Bud, but Miriam knew that Siobhan had developed a relationship with him, and one reason for coming here was to make her own assessment. She liked everything she saw about this blunt, can-do American aviator who had become so pivotal to the future of humankind; she was relieved that the project was in such evidently safe hands.

Not that her Eurasian pride would ever have allowed her to admit as much to President Alvarez.

She said, “I hope to meet some of your people later.”

“They will appreciate that.”

“So will I. I’m not going to pretend this isn’t a photo op for me; of course it is. But for better or worse this monstrous edifice will be my legacy. I was determined to come see it, and the people who are building it, before they kick me out.”

Bud nodded gravely. “We follow the polls too. I can’t believe how bad they are for you.” He smacked his fist against his palm. “They should send their damn questionnaires up here.”

She was touched. “It’s the way it goes, Colonel. The polls show people are broadly behind the shield project. But they are also suffering endless disruption because of all the wealth that is flowing off the planet and up here to this great orbiting sink of money. They want the shield, but they don’t like having to pay for it—and perhaps, beneath it all, they resent being faced with the threat of the sunstorm in the first place.”

Nicolaus grunted. “It is classic barroom psychology. When faced with bad news, after the denial comes the anger.”

Bud said, “So they need somebody to blame?”

“Something like that,” Miriam said. “Or perhaps they’re right. The shield will go on, whatever happens to me; we’ve gone too far to change direction now. But as for me—you know, Churchill lost an election right after winning the Second World War. The people judged he had done his job. Maybe my successor will do a better job of easing the day-to-day pain than I can.” And maybe, she wondered, the people sensed just how exhausted she was, how much this job had taken out of her—and how little she had left to give.

Nicolaus grunted. “You’re too philosophical, Miriam.”

“Yeah,” Bud growled. “What a dumb time to call an election! Maybe it should be postponed for a couple of years—”

“No,” she said firmly. “Oh, I suspect martial law will come to the cities before this is done. But democracy is our most important possession. If we throw it away when the going gets tough, we might never get it back—and then we’ll end up like the Chinese.”

Bud glanced sideways at Nicolaus, the furtive look of a man who had grown used to working under conditions of security. “Speaking of which—as you know we’re monitoring the Chinese from up here.”

“There have been more launches?”

“On a good day you can see them with the naked eye. You can’t hide the firing of a Long March booster. But no matter how we try, we can’t trace them after launch, by optical means, radar—we even tried bouncing laser beams off them.”

“Stealth technology?”

“We think so.”

It had been going on for a year: a massive and continuing program of space launches from China’s echoing interior, one huge mass after another hurled into the silence of space, their destination unknown. Miriam herself had been involved in efforts to figure out what was going on; the Chinese premier had deflected her probing without so much as raising a dyed eyebrow.

She said, “Anyhow it makes no difference to us.”

“Maybe,” Bud said. “But it pains me to think we’re laboring up here to save their skinny ungrateful butts too. Pardon my language.”

“You mustn’t think that way. Just remember, the mass of the people in China have little or no idea what their leaders are up to, and even less control. It’s them you are working for, not those gerontocrats in Beijing.”

He grinned. “I guess you’re right. You see, this is why you’d get my vote.”

“Sure I would…”

He pointed. “If you look up, you can see what it’s all about.”

She had to bend down to see.

There was the Earth. It was a blue lantern hanging directly opposite the position of the sun. Miriam was a million and a half kilometers from home, and from here the planet looked about the size of the Moon from Earth. And it was full, of course; Earth always was, as seen from here at L1, suspended between Earth and sun.

Earth hung low over the shield itself, and its pale blue light glistened from a glassy floor that stretched to a horizon that was already vanishingly distant. The emerging shield had yet to be positioned so that its face was correctly turned toward the sun; that would come in the final days before the sunstorm was due.

It was an astounding, beautiful sight, and it was almost impossible to believe that mere humans had made this thing, here in the depths of space.

On a warm impulse she turned to her press secretary. “Nicolaus, forget the damn cameras. You must see this view…”

He was cowering against the rear bulkhead of the chamber, his face twisted with an anguish she had never seen in him before. He rapidly composed himself. But it was an expression she would think of again, three days later, as Boudicca made its last descent to Earth.

On the way out of the observation deck, Miriam noticed a plaque, hastily carved from a bit of lunar glass:

ARMAGEDDON POSTPONED
COURTESY OF
U.S. ASTRONAUTICAL ENGINEERING CORPS

25: SMOKING GUN

For the reentry into Earth’s atmosphere aboard the spaceplane, Nicolaus chose to sit beside Miriam. He seemed stiff and rather silent, as he had been all the way back from the shield, and indeed for much of their time up there.

But Miriam, though she knew she was exhausted on some deep level, felt good. She stretched luxuriously. The big softscreens around her showed the broad blue-gray face of Earth below, and a pink glow building up at the leading edge of Boudicca‘s stubby wings as they bit into the thickening air. But there was no real sense of deceleration, only the mildest of vibrations, a tickle of pressure at her chest. It was all remarkably beautiful, and comfortable. “After seven days in space I feel wonderful,” she said. “I could get used to this. What a shame it’s over.”

“All things must end.”

There was something odd in Nicolaus’s tone. She looked at him, but though his posture remained stiff his face was blank. A distant alarm bell rang in her head.

She looked past Nicolaus across the narrow aisle to see Captain Purcell, who had been quiet for a while. Purcell’s head was lolling like a puppet’s.

Immediately she understood. “Oh, Nicolaus. What have you done?”

Siobhan arrived at the Chelsea flat, with Toby Pitt at her side. It was an ordinary place, Siobhan thought, and this was an unremarkable March day. But there was nothing unremarkable about the woman who opened the door.

“Thank you for coming,” Bisesa said. She looked tired—but then, Siobhan reflected, two years out from sunstorm day, everybody looked tired.

Siobhan followed her through the flat’s short hallway to the living room. The room had the clutter you would expect: a soft-looking sofa big enough for three, occasional tables littered with magazines and rolled-up softscreens. The main feature on which money had been spent was a big kid-friendly softwall. Bisesa was a single parent, Siobhan knew, with her one daughter, Myra, now eleven, at school today. The other tenant was Bisesa’s cousin, a student in bioethics who was now working on a pre-sunstorm conservation program run by an alliance of British zoos.

In a suit and tie, out of his natural environment in this domestic scene, Toby Pitt looked uncomfortable. “Nice softwall,” he said.

Bisesa shrugged. “It’s a bit out of date now. It kept Myra company when her squaddie mum was away. Now Myra has other interests,” she said with a mother’s fond exasperation. “And we don’t watch so much. Too much bad news.”

That was a common pattern, Siobhan knew. Anyhow, today the softwall was now hooked up to a government comms channel, and was showing the flickering images of Mikhail, Eugene, and others, images relayed from the Moon and Earth orbit to this living room in a flat in Chelsea.

Bisesa bustled away to make coffee.

Toby leaned toward Siobhan and said quietly, “I still think this is a mistake. To be pursuing theories of alien intention behind the sunstorm—people are becoming too disengaged as it is.”

Siobhan knew he had a point.

The impending sunstorm itself was bad enough for the public mood. Now the preparations for it were starting to bite significantly into people’s lives. Immense construction projects like the Dome were causing monumental traffic problems. Across the city routine work was being rushed or neglected, and that was starting to show; just the lack of fresh paintwork on London’s major buildings was making the place look shabby. Aside from the huge diversion of resources to the Dome, everybody was stockpiling, it seemed, and there was a continual plague of shortages in the stores. A recent upsurge of global terrorism and the subsequent wave of paranoia and security clampdowns had made things worse yet. It was a time of fretfulness and anxiety, a time from which people increasingly wanted to escape.

All the major news organizations reported catastrophic slumps in ratings—while sales of synth soap operas, which allowed you to pretend the outside world didn’t exist at all, had boomed. The world’s leaders were becoming concerned that if there was more bad news of any kind, everybody would just hide away at home until the dreadful dawn of April 20, 2042 finally put an end to all their stories.

“But,” Siobhan said slowly, “what if Bisesa’s right?” That was the slim, disturbing possibility that had guided her actions since the day Bisesa had first bluffed her way into the Royal Society, already more than a year ago, and why she had diverted a small percentage of the energies at her command to looking into Bisesa’s ideas. “If this is the truth, Toby, there’s no hiding away, whatever it costs.”

“I’m sorry,” he said quickly. “You have my full support. You know that. It’s just that I’ve always felt that putting Bisesa I-was-abducted-by-aliens-and-fell-in-love-with-Alexander-the-Great Dutt in touch with Eugene the-greatest-mind-since-Einstein-if-only-you-would-listen Mangles was asking for trouble.”

She forced a smile. “Yes, but what fun!”

Bisesa returned with a tray of coffees, and a pot for refills.

“There’s nothing you can do about it, Miriam,” Nicolaus said, his voice thickened by stress. “The plane’s communications are cut off, and anyhow we will soon be isolated by reentry plasma. Even Aristotle is out of touch. The fact that the plane is automated actually made it easier. The device is on a tamperproof timer, which, even if we could get to it—”

She held up her hands. “I really don’t want to know.” She glanced at the wall softscreens, which now showed a broadening glow, escalating through pink to white. It was like being inside a vast lightbulb, she thought. Must her life really end amid such beauty?

She searched for anger, but found only emptiness, a kind of pity. After years of strain she was fundamentally exhausted, she thought, too tired to be angry, even about this. And maybe she had thought that something like this was inevitable, in the end. But she did want to understand.

“What’s the point, Nicolaus? You know the polls better than I do. In six months I would be out of the way anyhow. And this really won’t make any difference to the project. If anything it’s likely to strengthen everybody’s resolve to get it done.”

“Are you sure?” His grin was tight. “This is quite a stunt, you know. You are Prime Minister of the world’s largest democracy. And nobody has taken down a spaceplane before. If confidence in flying into space is dented, even just a bit—if people on the shield start looking over their shoulders when they ought to be getting on with their work—I’ll have achieved what I set out to do.”

“But you won’t live to see it, will you?” And neither will I… “You’re just another in a long line of suicide bombers, as careless of the lives of others as you are of your own.”

He said coldly, “You don’t know me well enough to insult me. Even though I’ve worked at your side for ten years.”

Of course that was true, she thought with a stab of guilt. She remembered her resolution on the way out to try to get Nicolaus to open up a little—but on the shield she had been too entranced by her surroundings even to notice him. Would it have made any difference even if she had? Perhaps it was just as well, she thought morbidly, that she would not live long enough to be plagued by such questions.

“Tell me why, Nicolaus. I think you owe me that.”

His voice tight with tension, he said, “I sacrifice my life for El, the One True God.”

And that was enough to tell her everything.

Siobhan glanced at the faces on Bisesa’s softwall. “Everybody online? Can you see us?”

With the usual disconcerting lightspeed delays, the others responded.

“No introductions needed, no ceremony. Who wants to start—Eugene?”

When her words reached the Moon, Eugene visibly jumped, as if his attention had been fixed on something else. “Okay,” he said. “First some background. You’re aware of my work on the sun, of course.” The middle of the softwall filled up with an image of the sun, which then turned transparent to reveal onion-skin layers within. The heart of the sun, the fusing core—a star within a star—glowed a sullen red. It was laced by a crisscross pattern of dark and bright stripes, dynamic, elusive, ever shifting. There was a date stamp in the corner, showing today’s date, in March 2040. Eugene said, “These oscillations will lead in the near future to a catastrophic outpouring of energy into the external environment.”

Casually he ran the model forward in time, until the image suddenly flared.

Siobhan felt Toby flinch. He murmured, “He really doesn’t see the impact he has on the rest of us, does he? Sometimes that boy scares me more than the sun itself.”

“But he’s useful,” Siobhan whispered back.

Eugene said, “So the future projection is stable, reliable. But I have had more difficulty with projections into the past. Nothing in the standard models of stellar interior behavior served as a guide. I began to suspect a single impulsive event lay behind this anomalous condition—an anomaly behind the anomaly. But I had trouble converging on a model. My discussions with Lieutenant Dutt, after Professor McGorran put us in touch, gave me a new paradigm to work with.”

Siobhan murmured to Toby, “Told you so.”

Mikhail interceded, “I think you’d better just show us, son.”

Eugene nodded curtly and tapped at an out-of-shot softscreen.

The date stamp began to count down, and the reconstructed events ran backward. As wave modes fluttered across the surface of the core, detail appeared in sidebars: frequencies, phases, amplitudes, lists of the energy shares of the principal vibration modes. As interference, nonlinearity, and other effects worked on the three-dimensional waves, the core’s output peaked and dipped.

Mikhail commented, “Eugene’s model is remarkably good. We have been able to map many of these resonant-peak anomalies onto some of the notable solar weather incidents in our history: the Little Ice Age, the 1859 storm…”

Siobhan had studied wave propagation as applied to the early universe, and she could see the quality of the work here. She said to Toby, “If he gets this anywhere near right, it will be one of the keenest bits of analysis I’ve ever seen.”

“Finest mind since Einstein,” Toby said dryly.

Now things changed on the screen. The oscillations grew wilder. And it seemed to Siobhan that a concentration of energy was gathering in one place.

Unexpectedly a brilliant knot of light rose out of the core, like a gruesome dawn inside the body of the sun itself. And as soon as the knot had left the core, those central oscillations all but ceased.

Eugene paused his projection, leaving the point of light poised on the edge of the core but beneath the blanketing layers of sun above. “At this point my modeling of the core anomaly is smoothly patched to a new routine to project the behavior of the inert radiative zone that lies around the core, and—”

Siobhan leaned forward. “Hold it, Eugene. What is that thing?”

Eugene blinked. “A concentration of mass,” he said, as if it were obvious. He displayed graphs of density. “At this point the mass contained within three standard deviations of the center of gravity is ten to power twenty-eight kilograms.”

She did some quick mental arithmetic. “That’s about five Jupiters.”

Eugene glanced at her, as if surprised she would need a translation into such baby talk. “About that, yes.” He resumed his animation.

That glowing fist of matter rose out of the sun’s heart, up through its layers. As it rose Siobhan saw disturbances like ripples flowing into the mass knot, a glowing tail almost like a comet’s, preceding it on its way to the surface. But she was watching this projection in reverse, she reminded herself. In reality this lump of matter had slammed its way down into the sun, leaving a turbulent wake behind, dumping energy and mass into the sun’s tortured bulk through those mighty waves.

She said, “So that’s how the radiative zone was cut through.”

“Precisely,” Mikhail said. “Eugene’s model is elegant: a single cause to explain many effects.”

The knot of mass, backing out of the sun, now reached the surface and popped out through the photosphere. Again Eugene froze his animation. Siobhan saw that the emergence was close to the sun’s equator.

The date stamp, she noted, showed 4 B.C.

Eugene said, “Here is the moment of impact. The mass at this point was some ten to power—” He glanced at Siobhan. “About fifteen Jupiters. As it descended into the sun’s interior, the outer layers of the object were of course ablated away, but five Jupiters made it to the core.”

Toby Pitt said, “Fifteen Jupiters. It was a planet—a Jovian, a big one. And, two thousand years ago—it fell into the sun. Is that what you’re saying?”

“Not quite,” Eugene said. He tapped at his softscreen again, and the view abruptly changed. Now the sun was a bright pinpoint at the center of a darkened screen, and the planets’ orbits were traced out as shining circles. “From this point I made another patch, to a simple Newtonian gravity trajectory solution. Corrections for relativity aren’t significant until the impactor passed the orbit of Mercury, and even then they are small…”

Knowing where and how fast his mighty Jovian had splashed into the sun, Eugene had projected back, using Newton’s gravity law, to figure out the path it must have followed to get there. A glowing line, starting in the sun and crossing all the planets’ orbits, swept out of the solar system and off the screen. It curved subtly but was remarkably straight, Siobhan saw.

Toby said, “I don’t understand. Why do you say it didn’t fall into the sun?”

Siobhan said immediately, “Because that trajectory is hyperbolic. Toby, the Jovian was moving faster than solar escape velocity.”

Mikhail said somberly, “It didn’t fall into the sun. It was fired in.”

Toby’s mouth opened, and closed.

Bisesa didn’t seem surprised at all.

The One-Godders had emerged as a kind of reaction to the benevolent Oikumen movement. Fundamentalists of three of the world’s great faiths, Judaism, Christianity, and Islam, had appealed to their own shared roots. They united under the banner of the Old Testament God of Abraham, Isaac, and Jacob: Yahweh, who was thought to have derived from a still older deity called El, a god of the Canaanites.

And El was a meddling god, a brutish, partial, and murderous tribal god. In the late 2020s His first act, through His modern adherents, had been the destruction of the Dome of the Rock, when fanatics, in a self-destructive spasm, had used a nuclear grenade to take out a site of unique significance to at least two of their three intertwined creeds. Miriam remembered that Bud Tooke had been involved in the cleanup.

“Nicolaus, why would you want to impede the work on the shield? You’ve been at my side throughout. Can’t you see how important it is?”

“If God wishes us to be put to the fire of the sunstorm, so be it. And if He chooses to save us, so be it. For us to question His authority over us with this monstrous gesture—”

“Oh, can it,” she said irritably. “I’ve heard it all before. A Tower of Babel in space, eh? And you’re the one to bring it down. How disappointing, how banal!”

“Miriam, your mockery can’t hurt me anymore. I have found faith,” he said.

And there was the real problem, she realized.

In his conversion Nicolaus wasn’t alone. All the major faiths, sects, and cults worldwide had recorded a marked rise in conversions since June 9. You might expect a flight to God in the face of impending catastrophe—but there was a theory, still controversial and revealed to her only in confidential briefings, that increased solar activity was correlated with religious impulses in humans. The great electromagnetic energies that had washed over the planet since June 9 were, it seemed, able to work subtle changes in the complicated bioelectrical fields of a human brain, just as in power cables and computer chips.

If that was true—if the agitation of the sun had somehow led, by a long and complicated causal chain, to a lethal ideological determination in the mind of Miriam’s closest colleague to kill her—well, what an irony it would be. She said blackly, “If God exists, He must be laughing right now.”

“What did you say?”

“Never mind.” A thought struck her. “Nicolaus—where will we come down?”

He smiled coldly. “Rome,” he said.

Siobhan asked, “Can we say where this rogue planet came from?”

Not from the solar system, of course; it had been moving too fast to have been captured by the sun. Eugene displayed more of his “patched solutions,” projecting the path of his Jovian back to the distant stars. He rattled off celestial coordinates, but Siobhan stopped him and turned to Mikhail. “Can you put that into English?”

“Aquila,” Mikhail said. “It came to us out of the constellation of the eagle.” This was a constellation close to the sky’s equator; from Earth the plane of the Galaxy appeared to run through it. Mikhail said, “In fact, Professor McGorran, we know that this object must have came from the star Altair.” Altair was the brightest star in Aquila. It was some sixteen light-years from Earth.

Eugene cautioned, “Mikhail, I’m not sure we should talk about this. The projection gets fuzzy if you push it back that far. The error bars—”

Mikhail said grimly, “My boy, this is not a time for timidity. Professor, it appears that Eugene’s rogue Jovian originated in orbit around Altair. It was flung out after a series of close encounters with other planets in the system, which are visible with our planet-finder telescopes. The details are understandably sketchy, but we hope to pin them down further.”

“And,” Siobhan said, “it was hurled our way.”

Toby pulled his nose. “It seems fantastic.”

Mikhail said quickly, “The reconstruction is very reliable. It has been verified from multiple data sources using a variety of independent methods. I have checked over Eugene’s calculations myself. This is all quite authoritative.”

Bisesa listened to all this quietly, without reacting.

“Okay,” Toby said. “So a rogue planet fell into the sun. It’s an astonishing thing to happen, but not unprecedented. Remember Comet Shoemaker-Levy colliding with Jupiter in the 1990s? And—with respect—what does it have to do with Lieutenant Dutt and her theories about extraterrestrial intervention?”

Eugene snapped, “Are you such a fool that you can’t see it?”

Toby bit back, “Now look here—”

Siobhan grabbed his arm. “Just take us through it, Eugene. Step by step.”

Eugene visibly fought for patience. “Have you really no idea how unlikely this scenario is? Yes, there are rogue planets, formed independently of stars, or flung out of stellar systems. Yes, it may happen that such a planet could cross from one system to another. But it’s highly unlikely. The Galaxy is empty. To scale, the stars are like grains of sand, separated by kilometers. I estimate the chance of a planet like this coming anywhere near our solar system as being one in a hundred thousand.

“And this Jovian didn’t just approach us—it didn’t just fall near the sun—it fell directly into the sun, on a trajectory that would take it directly toward the sun’s center of mass.” He laughed, disbelieving at their incomprehension. “The odds against such a thing are absurd. No naturalistic explanation is plausible.”

Mikhail nodded. “Circumstantial, perhaps, but still… I’ve always thought Sherlock Holmes put it well. ‘When you have eliminated the impossible, whatever remains, however improbable, must be the truth.’ ”

“Somebody did this,” Toby said slowly. “That’s what you’re saying. Somebody deliberately fired a planet, a big fat Jovian, straight at our sun. We’ve been hit by a bullet from God.”

Bisesa said briskly, “Oh, I don’t think it has anything to do with God.” She stood up. “More coffee?”

“Nicolaus—your target is the Vatican?” But the destruction would be much more extensive than that. A spaceplane returning from orbit packed a lot of kinetic energy: the Eternal City would be hit by an explosion with the force of a small nuclear weapon. She had not felt like crying before, but now tears pricked her eyes: not for herself, but for the destruction that would come. “Oh, Nicolaus. What a waste. What a terrible—”

And then the bomb went off. It felt like a punch in the back.

She was still conscious, for a while. She could even breathe. The cabin had survived, and its systems were doing its best to protect her. But she could feel herself tumbling, and monstrous G-forces pushed her deep into her seat. She could hear nothing; the blast had left her deafened—not that it mattered anymore.

She was falling through the sky, she supposed, trapped in a piece of wreckage thrown out of a fireball high above Rome.

Still she felt no anger, no fear. Only sadness that she would not see the greatest job of her life through to the end. Sadness that she had had no chance to say goodbye to those she loved.

But she had been tired, she thought. So very tired. It was up to the others now.

In the last second she felt a hand creep into hers. Nicolaus’s, a last, raw human contact. She gripped it hard. Then, as the spinning worsened, she blacked out, and knew no more.

39: MORNING STAR

0300 (London Time)

On Mars, as on the Moon and on the shield, you officially kept Houston time. But you counted the sols, the Martian days, to mark the rhythms of your life.

And on this fateful morning, as she drove across the cold Martian ground, Helena Umfraville kept one small display showing her another time, the astronomers’ universal time—Greenwich Mean Time, one hour behind the local time in London. And when that display approached two A.M., a little before the sunstorm was predicted to start, she slowed the Beagle to a stop, clambered through the docking port into her suit, and stepped away from the rover.

In this corner of Mars it was dawn. She was facing the rising sun. On the horizon the light gathered to a coppery brown, and the rising sun was a dusty disk, attenuated by distance. The rest of the sky was a dome of stars.

This was the usual rock-strewn desert so characteristic of the northern plains. Once again she was standing on new Martian ground, ground marked by no human footprint. But this morning Mars didn’t matter, not compared with the great spectacle to come in the sky.

On the ground there wasn’t a single light to be seen. The huddled camp around the Aurora 1 landing site was already far away, beyond the cramped horizon. The crew had dug themselves a shelter in the Martian dirt that might, might, shield them from the worst of the sunstorm, whose ferocity would be diminished a little by Mars’s greater distance from the sun. Helena had to be back in the shelter soon if she hoped to live through this long sol.

But here she was, far from home, and stopped dead in the middle of nowhere. She didn’t feel she had a choice but to be here.

During the night the Aurora crew had received strange radio signals from around the planet, relayed by the tiny comsats they had placed in Martian orbit. Most of them had been simple beacons—but there had also been voices, heavily accented human voices, barely comprehensible: voices asking for help. It had been a moment as electrifying as Crusoe’s discovery of a human footstep on the beach of his island. Suddenly they weren’t alone on Mars; there was somebody else here—and that somebody was in trouble.

The priority was clear. On this empty planet, there was nobody but the Aurora crew to help. Some of the locations were on the planet’s far side, and would have to wait until a major expedition could be mounted using the Aurora‘s return-to-orbit shuttle. But three of the locations had been within a few hundred kilometers of Aurora, reachable with the rovers.

So three crew, including Helena, had set off in the rovers, seeking the sources of the nearby signals. They drove at night and alone, in defiance of all safety rules. Time was short; there was no choice.

And that was why Helena was here in the middle of nowhere, gazing up at the huge, cold Martian sky, with only the soft whir of her pressure suit fans for company.

The constellations, of course, were unchanged as seen from Mars: the immense interplanetary journey she had made was right at the limit of human capability, but it was dwarfed by the tremendous gulfs between the stars. But still she had crossed the solar system, and the view of the planets from here was quite different. If she looked over her left shoulder she could see Jupiter, a brilliant star in the scattered constellation of Opiuchus. Jupiter was a wonder from Mars, and some of the Aurora crew claimed you could actually see its moons with the naked eye. Meanwhile the Martian sky boasted three morning stars: Mercury, Venus, and Earth. Mercury, sharing Aquarius with the sun, was all but lost in the sun’s glare. Venus was a little to the right of the sun in Pisces, not quite as glorious as when seen from Earth.

And there was the home world itself, to the left of the sun, in Capricorn. Earth was quite unmistakable, a dazzling pearl with a hint of blue. Good eyes could make out the small, brownish satellite that traveled with its parent, the faithful Moon. As it happened, this morning all the inner worlds were on the same side of the sun as Mars—as if the four rocky planets were huddling together for protection.

Helena spoke softly, and the image was magnified by her visor, bringing Earth and Moon into sharp focus. This morning they were two fat crescents in identical phases, facing the sun that was about to betray them. All over the Earth and Moon people would be pausing in whatever they were doing and looking up at the sky, billions of pairs of eyes all turned in the same direction, waiting for the show to begin at last. Despite the urgency of her rescue mission, at such a moment she couldn’t be anywhere but here, out under the complex Martian sky, one with the rest of an apprehensive humankind, holding her breath.

A clock chimed softly. It was an alarm she had set up earlier, to sound at the precise moment of the breaking of the storm.

In the dawn sky nothing changed. It takes thirteen minutes for light to travel from the sun to Mars. But Helena knew that already the electromagnetic fury of the sunstorm must be spilling out across the solar system.

She stood in Martian dust, in solemn silence. Then she walked back to her rover to resume her mission.

40: DAWN

0307 (London Time)

Bisesa and Myra, unable to sleep, sat huddled on the floor of their living room, arms wrapped around each other. Rising from the city beyond the walls of the flat they could hear drunken shouts, smashing glass, the wails of sirens—and occasional deep bangs, like doors slamming, that might have been distant explosions.

A candle flickered in its holder on the floor. A few battery-powered torches lay to hand, along with other essentials: a hand-cranked radio, a comprehensive first-aid kit, a gas stove, even firewood, though the flat lacked a hearth. Away from this room, the flat was dark. They had taken official advice and shut down almost everything electrical or electronic. It was a “blackout” order, the Mayor had said—not wholly accurate, but another deliberate echo of World War II. But they had kept the power on for the air-conditioning, without which, in the increasingly smoggy air of the Dome, they would quickly get uncomfortable. And they hadn’t been able to bear killing the softwall. Somehow not knowing what was happening would have been worst of all.

Anyhow, from the noise outside it sounded as if nobody else was paying much attention to the Mayor’s entreaties either.

The giant softwall was still working. With commentary delivered by somber talking heads, it brought them a mosaic of scattered images from around the planet. On the night side some cities were darkened by the blank circles of domes, while others burned in a final frenzy of partying and looting. Other images came from a daylit hemisphere that had not known a proper sunrise that morning, for the shield blocked all but a trickle of the sun’s light. Even so, as the sun climbed higher in the sky, cultists and ravers danced in its ghostly glow.

In these last moments before the storm, the image that kept catching Bisesa’s eye was of the solar eclipse. The picture came from a plane that had been flying in the eclipse’s shifting shadow for more than an hour. Right now it was over the western Pacific, somewhere off the Philippines. In a sense this was a double eclipse, of course, the Moon’s shadow reinforcing that of the shield, but even in this reduced trickle of light the sun provided its usual beautiful spectacle, with the thread-like corona like the hair of the Medusa from which Athena’s shield was intended to protect the Earth.

The observing plane wasn’t alone in the sky. A whole fleet of aircraft tracked the Moon’s shadow as it scanned across the face of the Earth, and on the ocean below, ships, including one immense liner, huddled along the track of totality. To shelter beneath the shadow of the friendly Moon was one of the more rational strategies people had dreamed up to avoid the sunstorm’s gaze, and thousands had crowded into that band of shaded ocean. Of course it was futile. In any given site the duration of the eclipse’s totality was only a few minutes, and even on one of those shadow-chasing planes there was only a bit more than three hours’ shelter to be had at best. But you couldn’t blame people for trying, Bisesa supposed.

Somehow this neat bit of celestial clockwork made the dreadful morning real for Bisesa. The Firstborn had arranged the storm for this precise moment, with this cosmic coincidence bright in Earth’s sky. They had even had the arrogance to show her what they intended. And now here it was, unfolding just as they had planned, live on TV—

Myra gasped. Bisesa clutched her daughter.

In that eclipse image, light gushed around the blackened circle of the Moon, as if an immense bomb had gone off on the satellite’s far side. It was the sunstorm, of course. Bisesa’s clock showed it was breaking at the very second Eugene Mangles had predicted. There was a brief, tantalizing glimpse of eclipse-tracking planes falling out of the sky.

Then that bit of the softwall flickered, fritzed, and turned to the sky blue of no feed. One by one the other segments of the softwall winked out, and the talking heads fell silent.

On board the Aurora 2, the shield’s mission controllers broke out bags of salted peanuts.

Bud Tooke grabbed a bag of his own. This was an old good-luck tradition that derived from JPL—the Jet Propulsion Laboratory in Pasadena—which had always handled NASA’s great unmanned spacecraft, and which had supplied key personnel and wisdom for this project. Now’s the time for luck, Bud thought.

One big softscreen was dedicated to showing a view of the whole Earth.

From the point of view of Bud’s mission control room, right at the center of the shield, celestial geometry was simple. Here at L1 the shield hung forever between sun and Earth. So from Bud’s point of view the Earth was always full. But today, right on cue, the Moon had moved between sun and Earth, and so was sailing through the shield’s tunnel of shadow—a tunnel nearly four times as wide as the Moon itself. Bud could even make out the deeper shadow that the Moon cast on the face of the Earth, a broad gray disk passing over the Pacific. This remarkable alignment was seen in a ghostly, reduced light, for the shield was doing its job of turning aside all but a trickle of sunlight.

When the storm broke, the Moon’s illuminated face flared a fraction of a second before the hail of light splashed against the face of the Earth.

Bud turned immediately to his people. He surveyed rows of faces, the people in the room with him, or transmitted from across the face of the shield and the Moon. He saw shocked, blanched expressions, mouths round. Bud had always insisted on full mission control discipline, to the standards honed by NASA across eighty years of manned spaceflight. And that discipline, that focus, was more important now than ever.

He touched his throat microphone. “This is Flight. Let’s get to work, folks. We’ll go around the loop. Ops—”

Rose Delea was surrounded by a tent of softscreens; for this critical day he had put her in overall charge of shield operations. “Nominal, Flight. We’re taking a battering from the hard rain, everything from ultraviolet to X-rays. But we’re holding for now, and Athena is responding.”

While the peak energy of the storm was expected to be in the visible light spectrum, there was plenty of shit pouring down at shorter wavelengths too—not to mention the immense flare that had kicked off yesterday. The electronic components of the shield had been hardened to military standard, and the people were protected too, as far as possible. There would be losses of the shield’s capacity, and among the crew. It was going to be painful, but enough slack had been built into the design that the shield should get through.

But there was nothing they could do for the Earth. The shield had been designed to cope with the peak-energy bombardment in the visible and near-infrared spectrum, which would soon cut in; this preliminary sleet of X-rays and gamma rays would pass through its structure as if it didn’t exist. They had always known it would be like this: the shield was engineering, not magic, and couldn’t deflect it all. They had had to make hard choices. You did your best, and moved on. But it was agonizing to sit up here knowing you could offer the Earth no help, none at all.

“Okay,” Bud said. “Capcom, Flight.”

“Flight, Capcom,” Mario Ponzo called. “We’re ready for when you call on us, Flight.”

“Let’s hope we don’t have to for a while yet.”

Mario, pilot of an Earth–Moon shuttle, had volunteered for a position up here after he had met Siobhan McGorran during one of her jaunts to the Moon. Mario was responsible for communicating with the maintenance crews who stood ready in their hardened spacesuits to go out into the storm. Bud had given him the title of Capcom—“capsule communicator.” Like Bud’s own job title of Flight Director, “Capcom” was a bit of NASA jargon that dated from the days of the first Mercury flights, when you really did have to communicate with a man in a capsule. But everybody knew what it meant, and it was a word that carried its own traditions. Mario had his traditions too, in fact; he was the most heavily bearded man on the shield, superstitiously unwilling to shave in space.

Next: “Surgeon?”

They had tried to prepare for the hard rain. All the shield’s workers and command crew had been dosed up with medications designed to counter radiation toxicity, such as free radicals to shield molecular lesions in DNA, and chemoprevention agents that might hinder the deadly progression from mutation to cancer. For radiation casualties they had stocks of frozen bone marrow and agents—such as interleukins—to stimulate the production of blood cells. Trauma units were ready to treat injuries caused by crush, pressure, heat, burns—all likely consequences of the physical dangers of working out on the shield. The medical team on the shield was necessarily small, but it was supported by diagnostic and treatment algorithms coded into Athena, and remotely by teams of experts on Earth and the Moon, though nobody was sure how long the links to home might stand up.

For now the doctors and their robotic assistants were as ready as they could be, ready for the casualties they all knew would come; there was nothing more to be done. It would have to do.

Bud moved on. “Weather, Flight.”

Mikhail Martynov’s gloomy voice reached Bud after the usual few seconds’ delay. “Here I am, Colonel.” Bud could see Mikhail’s somber face, with Eugene Mangles in the background, in their lab at Clavius Base. “Weather” meant solar weather; Mikhail was the top of a pyramid of scientists on Earth, Moon, and shield, all monitoring the sun’s behavior as it unfolded. Mikhail said, “Right now the sun is behaving as we predicted it would. For better or worse.”

Eugene Mangles murmured something to him.

Bud snapped, “What was that?”

“Eugene reminds me that the X-ray flux is a little higher than we predicted. Still within the error bars, but the trend is upward. Of course we have to expect some deviance; from the point of view of the energy output of the event, the X-ray spectrum is a sidebar, and we are looking at discrepancies among second-order predictions…”

On he talked. Bud tried to control his patience. Martynov, with his ignoring of call-sign protocol and his typical scientist’s tendency to make a lecture rather than to deliver a report, might be a liability later, when the pressure mounted. “Okay, Mikhail. Let me know if—”

But his words cut across a new time-lagged message from Mikhail. “I thought you might…” Mikhail hesitated as Bud’s truncated speech reached him. “You might like to see what is going on.”

“Where?”

“On the sun.”

His glum face was replaced by a false-color image compiled from an array of satellites and the shield’s own monitors. It was the sun—but not a sun any human would have recognized even a few hours ago. Its light was no longer yellowish but a ferocious blue-white, and huge glowing clouds drifted across its surface. From the edges of the disk streamers of flame erupted into space, dragged into arches and loops by the sun’s tangled magnetic field. And at the very center of the sun’s face there was a patch of searing light. Foreshortened, it was the most monstrous outpouring of all, and it was aimed directly at the Earth.

“Dear God.”

Bud’s head snapped around. “Who said that?”

“Sorry, Bud—umm, Flight. Flight, this is Comms.” An able young woman called Bella Fingal, whom Bud had placed in overall control of all aspects of communications. “I’m sorry,” she said again. “But—look at the Earth.”

All their faces turned to the big softscreen.

At L1 the shield was always positioned over the subsolar point, the place on Earth where the sun was directly overhead. Right now that point was over the western Pacific. And over the water, clouds were gathering in a rough spiral: a massive storm system was brewing. Soon that focus would track westward, passing over lands crowded with people.

“So it’s begun,” Rose Delea murmured.

“It would be a hell of a lot worse if not for us,” Bud snapped. “Just remember that. And keep your shape.”

“We’ll get through this together, Bud.”

It was Athena’s voice, spoken softly into his ear. Bud glanced around, unsure if anybody else had been meant to hear.

To hell with it. “Okay,” he said. “Who’s next on the loop?”

On Mars, Helena patiently drove her Beagle, waiting for the show to begin. In the space program you got used to waiting.

In the last moment she allowed herself a flicker of hope that the analysts might, after all, have got this wrong, that the whole thing might be some gruesome false alarm. But then, right on cue, the sun blossomed.

The rover’s windows instantly blackened, trying to protect her eyes, and the vehicle rolled to a halt. She spoke softly to the rover’s smart systems. As the windshield cleared she saw a dimmed sun, distorted by a pillar of light pushed out of the sun’s edge, blue-white, like a monstrous tree of fire rooted in its surface.

The light that reached her directly from the sun arrived before light reflected from the inner planets. But now each of the planets lit up like a Christmas light, one by one in a neat sequence: Mercury, Venus—and then Earth, toward which that brutal pillar of fire was unambiguously directed. It was real, then.

And beside Earth a new light in the sky sparked. It was the shield, bright as a star in the sunstorm light, a human-made object visible from the surface of Mars.

She had work to do, and not long to complete it. She overrode the Beagle‘s safety blocks and drove on.

In London sunrise was due a little before five A.M. Half an hour before that, Siobhan McGorran took a ride up the Euro-needle’s elevator shaft.

The shaft rose from the roof of the Needle all the way up through the air to the curving ceiling of the Dome itself. In extremis, this was an escape route, up through the roof of the Dome—though the details of what help would be available beyond that point had always been a bit sketchy. It was one of the few concessions the Prime Minister had made to protect his people.

The shaft was punctured by unglazed windows, and as Siobhan rose up, inner London opened out beneath her.

Street lighting had been cut back to a minimum, and whole areas of the capital lay in darkness. The river was a dark stripe that cut through the city, marked only by a few drifting sparks that could be police or Army patrols. But light blazed from various all-night parties, religious gatherings, and other events. There was plenty of traffic around too, she saw by the streams of headlights washing through the murky dark, despite the Mayor’s admonitions to stay home tonight.

Now the roof closed over her. She caught a last glimpse of girders and struts, maintenance robots hauling themselves about like squat spiders, and a few London pigeons, peacefully roosting under this tremendous ceiling.

The elevator rattled to a halt, and a door slid open.

She stepped out onto a platform. It was just a slab of concrete fixed to the curving outer shell of the Dome—open to the air, and a chill April-small-hours breeze cut through her. But it was quite safe, surrounded by a fine-mesh fence twice as high as she was. Doors out of the cage led to scary-looking ladders down which, she supposed, you could clamber to the ground if all else failed.

Two beefy soldiers stood on guard. They checked her ident chip with handheld scanners. She wondered how often these patient doorkeepers were relieved—and how long they would stay at their post when the worst of the storm hit.

She stepped away from the soldiers and looked up.

The predawn sky was complicated. Broken clouds streamed from east to west. And to the east, a structured crimson glow spread behind the clouds, sheets and curtains rippling languidly. It was obviously three-dimensional, a vast superstructure of light that towered above the night-side Earth. It was an aurora, of course. The high-energy photons from the angry sun were cracking open atoms in the upper atmosphere and sending electrons spiraling around Earth’s magnetic field lines. The aurora was one consequence, and the least harmful.

She stepped to the platform’s edge and looked down. The roof of the Dome was as smooth and reflective as polished chrome, and the aurora light returned complex, shimmering reflections from it. Though the bulk of the Tin Lid obscured her view, she could see the landscape of Greater London sprawled around the foot of the Dome. Whole swaths of the inner suburbs were plunged into darkness, broken by islands of light that might have been hospitals, or military or police posts. But elsewhere, just as inside the Dome, she saw splashes of light in areas where people were still defiantly ripping up the night, and there was a distant pop of gunfire. It was anything but a normal night—but it was hard to believe, gazing down at the familiar, still more or less unblemished landscape, that the other side of the world was already being torched.

One of the soldiers touched her shoulder. “Ma’am, it will be dawn soon. It might be better to get below.” His accent was a soft Scottish. He was very young, she saw, no more than twenty-one, twenty-two.

She smiled. “All right. Thank you. And take care of yourself.”

“I will. Good night, ma’am.”

She turned and made for the elevator. The aurora was actually bright enough to cast a diffuse shadow on the concrete platform before her.

In Bisesa’s flat, another alarm beeped softly. She glanced at its face by the blue light of the useless softwall.

“Nearly five,” she said to Myra. “Time for dawn. I think—”

The beeping stopped abruptly, and the watch face turned black. The wall’s blue glow surged, flickered, died. Now the only light in the room was the dim flickering of the candle on the floor.

Myra’s face was huge in the sudden gloom. “Mum, listen.”

“What?—oh.” Bisesa heard a weary clatter that must be an air-conditioning fan shutting down.

“Do you think the power has gone off?”

“Maybe.” Myra was going to speak again, but Bisesa held up her finger for hush. For a few seconds they both just listened.

Bisesa whispered, “Hear that? Outside the flat. No traffic noise—as if every car stopped at once. No sirens either.”

It was as if somebody had waved a wand and simply turned off London’s electricity—not just the juice that came from the big central power stations, but the independent generators in the hospitals and police stations, and car batteries, and everything else, right down to the cell batteries in the watch on her wrist.

But there was noise, she realized: human voices calling, a scream, a tinkle of glass—and a crump that must be an explosion. She stood and made for the window. “I think—”

Electricity crackled. Then the softwall blew in.

Myra screamed as shards of glass rained over her. Bits of electronics, sparking, showered over the carpet, which began to smolder. Bisesa ran to her daughter. “Myra!”

41: THE PALACE IN THE SKY

0704 (London Time)

Siobhan had spent the two hours since dawn in the big operations center that had been set up on a middle floor of the Euro-needle. The walls were plastered with giant softscreens, and people worked at rows of desks, their own flickering screens in front of them. Here the Prime Minister of Eurasia tried to keep tabs on what was going on across his vast domains, and around the rest of the planet. There was an air of frantic energy, almost of panic.

Right now the big problem was not the sunstorm’s heat but its electrical energy. It was the EMP, of course: the electromagnetic pulse.

The shield’s design had been optimized to handle the worst threat facing Earth, the storm’s big peak of energy in the visible spectrum. But along with that visible light had come flooding at lightspeed a dose of high-frequency radiation, gamma rays and X-rays, against which the shield could offer no protection. The invisible crud from space was hazardous for an unprotected astronaut; Siobhan knew that Bud and his shield crews were taking shelter where they could. Earth’s atmosphere was opaque to the radiation, and would save the planet’s population from the direct effects. But it was secondary consequences that were causing the problems.

The radiation itself might not reach the ground, but the energy carried by all those vicious little photons had to be dumped somewhere. Each photon smashed into an atom of the Earth’s high atmosphere, knocking free an electron. The electrons, electrically charged, were trapped by Earth’s magnetic field, soaking up more and more energy from the radiation falling from space, and they moved ever faster—and at last gave up their energy as pulses of electromagnetic radiation. So, as the Earth relentlessly turned into the sunstorm’s blast, a thin, high cloud of tortured electrons migrated across the planet, raining energy down onto the land and sea.

The secondary radiation would pass through human flesh as if it weren’t there. But it induced surges of current in long conductors like power lines, or even long aerials. Appliances suffered surges of power that could be enough to destroy them or even make them explode: power failed in every building across London, every stove or electric heater became a potential bomb. It was like June 9, 2037 all over again, even if the root physical cause was subtly different.

The authorities had had years’ warning of this. They had even dug out a set of dusty old military studies. The EMP effect had been discovered by accident, when an atmospheric bomb test had unintentionally knocked over the telephone system in Honolulu, more than a thousand kilometers away. Once it had been seriously suggested that by detonating a massive enough nuclear bomb high above the atmosphere over a likely battlefield, the enemy’s electronics could be fried even before the fighting started. So there were decades of experience of military-hardening equipment to withstand this sort of jolt.

In London, government gear had, where possible, been toughened to military specifications, and had been augmented by backups: optical cables, for instance, were supposedly unaffected. Those Green Goddess fire engines were back in action tonight, and London’s police were out patrolling in very quaint-looking vehicles, some of which had been brought out of retirement in museums. It was easy to fuse modern integrated circuits, full of tiny gaps ready to be breached by sparks, but older, more robust gear, such as antique cars built before about 1980, could handle the worst of it. The final precaution in London had been the “blackout order.” If people just switched their equipment off, there was a better chance it might survive.

But there wasn’t time to fix or replace everything, and not everybody was going to sit at home in the dark. There had already been vehicle collisions all over London, and beyond the Dome there were reports of planes, which shouldn’t have been flying anyhow, dropping out of the sky like flies. Modern planes depended on active electronic control of their aerosurfaces to keep them in the air; when their chips failed, they couldn’t even glide home.

Meanwhile, only one in a hundred phones was going to live through this, as were few exchanges and transmission stations, and far above, satellites were popping out of the electronic sky. Soon the great electronic interconnection on which much of humankind’s business depended was going to fail—in the end the disruption would be far worse than June 9—and just when they needed it most.

“Siobhan, I’m sorry to interrupt—”

Siobhan knew that as an entity emergent from the web of global interconnection, Aristotle was peculiarly vulnerable tonight. “Aristotle. How are you feeling?”

“Thank you for asking,” he said. “I do feel a little odd. But the networks on which I am based are robust. They were designed in the first place to withstand attacks.”

“I know. But not this.”

“For now I can soldier on. Besides I have contingency plans, as you know. Siobhan, I have a call for you. I think it may be important. It is from overseas.”

“Overseas?”

“To be precise, Sri Lanka. It is from your daughter—”

“Perdita? Sri Lanka? That’s impossible. I put her down a salt mine in Cheshire!”

“Evidently she didn’t stay there,” Aristotle said gently. “I’ll put you through.”

Siobhan looked around wildly until she found a whole-Earth image, beamed down from the shield. The subsolar point was now tracking its way across eastern Asia. This point, where at any moment the maximum energy flux was being dumped into the atmosphere, was the center of a vicious spiral of tortured cloud. And all across the daylit hemisphere of the planet, as water evaporated from ocean and land, huge storm banks were gathering.

In Sri Lanka it would soon be high noon.

Beside a wall of Sigiriya, Perdita crouched in the sodden dirt. This “palace in the sky” had stood for thirteen centuries, even though it had been abandoned and forgotten for most of that time. But it was affording her no shelter now.

The sky was a dark lid, covered with boiling clouds, with only a pale glow to show the position of the treacherous sun, almost directly overhead. The wind swirled around the ancient stones, slamming her in the face and chest. The air carried warm rain that lashed into her eyes, and it was hot, hot as hell, despite its speed. “It’s like an explosion in a sauna”—that was what Harry had said, her Australian boyfriend, who had suggested coming out here in the first place. But she hadn’t seen Harry or anybody else for long minutes.

The wind shifted again, and she got a mouthful of rain. It tasted of salt, seawater dragged straight up from the oceans.

Her phone was a heavy milspec number her mother had insisted she carry with her at all times over the last two months. She was amazed it still worked. But she had to scream into it to make herself heard over the wind. “Mother?”

“Perdita, what the hell are you doing in Sri Lanka? I put you down that mine to be safe. You stupid, selfish—”

“I know, I know,” Perdita said miserably. But to sneak away had seemed a good idea at the time.

She had first visited Sri Lanka three years ago. She had immediately fallen in love with the island. Though still sometimes torn by the conflicts of the past, it seemed to her a remarkably peaceful place, with none of the litter and crowds and awful gulf between rich and poor that marred India. Even the prison in Colombo—where she had spent one night when, fueled by too much palm toddy, she had joined Harry in an overvigorous protest outside the Indonesian embassy over logging contracts—had seemed remarkably civilized, with a large sign over its entrance saying PRISONERS ARE HUMAN BEINGS.

Like many visitors she had been drawn to the ‘Cultural Triangle’ at the heart of the island, between Anuradhapura, Polonnaruwa, and Dambulla. It was a plain littered with huge boulders and carpeted by a jungle of teak, ebony, and mahogany. Here amid the wildlife and the beautiful villages lurked astounding cultural relics, such as this palace, which had been occupied for only a couple of decades before being lost in the jungle for centuries.

Perdita had never felt happy just to hide out in a hole in the ground in Cheshire. As the sunstorm date had approached, and the authorities worldwide labored to protect cities, oil wells, and power plants, a movement had gathered among the young to try to save some of the rest: the peripheral, unfashionable, ruined, ignored. So when Harry had suggested coming to Sri Lanka to try to save some of the Cultural Triangle, she had jumped at the chance, and slipped away. For weeks the young volunteers had gamely collected seeds from the trees and plants, and chased after the wildlife. Perdita’s biggest project had been to clamber over Sigiriya in an attempt to wrap it up in reflective foil—like a huge Christmas turkey, as Harry had said.

She supposed she hadn’t really believed the dire predictions of what would happen when the sunstorm hit—if she had, she probably would have stayed down that mine in Cheshire after all, and pulled Harry in after her. Well, she had been wrong. Her mother had told her the shield’s goal was to cut the incoming solar heat to a thousandth of what might otherwise have hit the planet. It was unbelievable: if this was just a thousandth, what would the full force of the storm have been like?

“The wrapping blew off Sigiriya in a minute,” Perdita yelled miserably into the phone. “And half the trees have blown down, and—”

“How did you get out of that damn mine? Do you have any idea of the strings I had to pull to get you in there?”

“Mother, this isn’t doing any good. I’m here now.”

She could sense Siobhan trying to be calm. “Okay. Okay. Find shelter. Stay there. Keep your phone on. I’ll make some calls. Some of the GPS is down, but they may be able to locate you—”

The wind picked up even more, punching her like a great damp fist. “Mother—”

“I’ll contact the military on the island—the British consulate—”

“Mum, I love you!”

“Oh, Perdita—”

But then the phone sparked in her hand, she dropped it, and it was gone.

And the wind lifted her clean off the ground.

It picked her up the way her father used to when she was very small. The air was hot, wet, and full of debris, and the wind tore so fast she could barely breathe. But, oddly, it was almost relaxing, to be blown like a leaf. She never even saw the great teak trunk, a bit of debris flung into the air as she was, which ended her life.

42: NOON

1023 (London Time)

On the Moon, Mikhail Martynov sat with Eugene Mangles.

Its walls plastered with softscreens and comms links, and now populated by patient workers murmuring into microphones, this had been Bud Tooke’s office when he was in command here at Clavius—but now, of course, Bud was up there at L1 risking his life, while Mikhail sipped coffee and watched pretty pictures.

“There is absolutely nothing we can do now,” Mikhail said. “Nothing but watch, and record, and learn for the future.”

“You said that before,” Eugene groused. With an impulsive movement he pushed back his chair and stalked around the office.

Mikhail considered calling him back, but thought better of it. He had spoken more for himself than for Eugene. Besides, he had no real idea what Eugene was feeling. The boy remained enigmatic to him, even now, after they had worked together so closely and so long. As so often, Mikhail was consumed with a desire to hold Eugene, to comfort him. But that, of course, was impossible.

As for Mikhail himself, his dominant emotion was guilt.

He turned to the big softscreen at the head of the room, with its portrait of the full Earth. Assembled from more than a hundred data feeds, this was an immense and detailed image of a planet, even better than Bud’s imagery on the shield, and really quite beautiful, Mikhail thought sadly. But it was a portrait of a planet in torment.

As the Earth helplessly rotated, the subsolar point had been tracking west. It was as if the planet were turning into a blowtorch. Right now the dry face of Africa was turned toward him, the continent’s familiar outline clearly recognizable. But an immense storm system thousands of kilometers across lay sprawled over the Sahara, and the continent’s green heart was streaked by vast black plumes of smoke: the last of the rain forests will die today, Mikhail thought desolately. And as the vegetation burned off the land, the oceans gave up huge volumes of moisture to the clouds.

By now no part of the world, even those regions still in the shelter of night, had been spared the effects of the sunstorm. Clouds boiled all across the visible face of the Earth, and as they streamed away from the equator and hit the cooler air over higher latitudes they dumped their water in ferocious rainstorms, and as snow at the poles. Meanwhile, as solar energy poured into Earth’s brimming heat reservoirs, the ocean currents, huge saltwater Amazons, were stirring and churning, and even while an unprecedented load of snow landed on Antarctica, all around the edge of the southern continent billions of tonnes of ice were breaking away from ice sheets.

And over the poles aurorae crackled, an eerie fire visible even from the Moon.

Seven hours into this horror, Mikhail thought. And many more hours to go, if Eugene’s final models proved accurate. There had been some modeling of the long-term effects of all this on Earth’s climate, but unlike Eugene’s models of the sun, no precision was possible. Nobody knew what would come of this—or even if anybody could survive on Earth to see it.

But no matter what became of Earth, Mikhail could confidently predict that he would live through the day—and that was the source of his guilt.

At this moment the Moon, new as seen from Earth, had its backside squarely positioned toward the treacherous sun. So there was a wall of inert rock three thousand kilometers thick between the storm and Mikhail’s own precious skin, here on the Moon’s Earth-facing side. Not only that but the Moon, close enough to the Earth–sun line to have cast its own shadow on the homeworld today, was fortuitously protected by the shield that had been built to save Earth. So Clavius was about as safe a place as it was possible to be today, anywhere in the inner solar system.

Almost all of the Moon’s inhabitants lived on the near side anyhow, but today those few who inhabited Farside bases, at Tsiolkovski and elsewhere, had been brought to the safety of Clavius and Armstrong. Even Mikhail’s customary eyrie at the Moon’s South Pole had been abandoned, although the patient electronic monitors there continued to study the sun’s extraordinary behavior, as they would with unvarying efficiency until they melted.

And so while Earth roiled and thrashed, while heroes strove to maintain the shield, here Mikhail lurked. How strange that his career, a lifetime dedicated to the study of the sun, should come to this, to cowering in a pit as the sun raged.

But then, perhaps, his destiny had been shaped long before he was born.

As he had once tried to explain to Eugene, there had always been a deep heliophilic strand in Russian astronautics. When Orthodox Christianity had split from Rome, it had reached back to more ancient pagan elements—especially the cult of Mithras, a mystery cult exported from Persia across the Roman Empire, in which the sun had been the dominant cosmic force. Over the centuries elements of these pagan roots had been preserved, for example in the painting of sun-like haloes in Russian iconography. It had been revived more explicitly by the “neo-pagans” of the nineteenth century. These holy fools might have been forgotten—had it not been for the fact that Tsiolkovski, father of Russian astronautics, had studied under heliophilic philosophers.

No wonder that Tsiolkovski’s vision of humanity’s future in space had been full of sunlight; indeed, he had dreamed that ultimately humankind in space would evolve into a closed, photosynthesizing metabolic unit, needing nothing but sunlight to live. Some philosophers even regarded the whole of the Russian space program as nothing but a modern version of a solar-worshiping ritual.

Mikhail himself was no mystic, no theologian. But surely it wasn’t a coincidence that he had been so drawn to the study of the sun. How strange it was, though, that now the sun should repay such devotion with this lethal storm.

And how strange it was too, he reflected, that the name given by Bisesa Dutt’s companions to their parallel world, Mir, meant not just “peace” or “world,” but was also the root of the name Mithras—for mir meant, in ancient Persian, “sun”…

He kept such thoughts to himself. On this terrible day he must focus not on theology but on the needs of his suffering world, of his family and friends—and of Eugene.

Eugene’s big college-athlete body was too powerful for the Moon’s feeble gravity, and as he paced he bounded over the polished floor. Fitfully he studied the graphs displayed on the softscreens, which showed how the sun’s actual behavior was tracking Eugene’s predictions. “Almost everything’s still nominal,” he said.

“Only the gammas are drifting upward,” Mikhail murmured.

“Yes. Only that. The perturbation analysis must have gone wrong somewhere. I wish I had time to go over it again…” He continued to worry aloud at the problem, talking of higher-order derivatives and asymptotic convergence.

In common with most real-world mathematical applications, Eugene’s model of the sun was like a math equation too complex to solve. So Eugene had applied approximation techniques to squeeze useful information out of it. You took some little bit of it you could understand, and tried to push away from that point in solution space step by step. Or you tried to take various parts of the model to extremes, where they either dwindled to zero or converged to some limit.

All these were standard techniques, and they had yielded useful and precise predictions for the way the sun was going to behave today. But they were only approximations. And the slow, steady divergence of the gamma ray and X-ray flux away from the predicted curve was a sign that Eugene had neglected some higher-order effect.

If Mikhail had been peer-reviewing Eugene’s work, the boy would certainly have come in for no criticism. This was only a marginal error, something overlooked in the residuals. In fact a divergence of fact from prediction was a necessary part of the feedback process that improved all scientific understanding.

But this wasn’t just a scientific study. Life-and-death decisions had been based on Eugene’s predictions, and any mistakes he had made could be devastating.

Mikhail sighed heavily. “We could never save everybody, no matter what we did. We always knew that.”

“Of course I understand that,” Eugene said with a sudden, startling snarl. “Do you think I’m some kind of sociopath? You’re so damn patronizing, Mikhail.”

Mikhail flinched, hurt. “I’m sorry.”

“I have family down there too.” Eugene glanced at Earth. America was turning into the storm, waking to a dreadful dawn; Eugene’s family were about to feel the worst of it. “All I could ever do for them is the science. And I couldn’t even get that right.”

He paced, and paced.

One-eye was frustrated and confused.

Tuft had defied him again. When he had found the fig tree with its thick load of fruit the younger male had failed to call the rest of the troop. And then, when challenged, Tuft had refused to yield to One-eye’s authority. He had just continued to push the luscious fruit into his thick-lipped mouth, while the rest of the troop pant-hooted at One-eye’s discomfiture.

By the standards of any chimpanzee troop, this was a severe political crisis. One-eye knew Tuft had to be dealt with.

But not today. One-eye wasn’t as young as he was, and he was stiff and aching after a restless sleep. And besides it was another hot, still, airless day, another day of the peculiar gloom that had swept over the forest, a day when you felt like doing nothing much but lying around and picking at your fur. He knew in his bones he wasn’t up to taking on Tuft today. Maybe tomorrow, then.

One-eye slunk away from the troop and moodily began to climb one of the tallest trees. He was going to bed.

In his own mind he had no name for himself, of course, any more than he had names for the others of the troop—although, as an intensely social animal, he knew each of them almost as well as he knew himself. “One-eye” was the name given him by the keepers who watched over the troop and the other denizens of this fragment of the Congolese forest.

At twenty-eight, One-eye was old enough to have lived through the great philosophical change that had swept over humankind, leading to his own reclassification as Homo, a cousin of humans, rather than Pan, a “mere” animal. This name change ensured his protection from poachers and hunters, of the kind that had put a bullet into his eye when he was younger than Tuft.

And it ensured his protection by his cousins now, on this worst day in the long history of humankind, and indeed of apes.

He reached the treetop. In his rough nest of folded-over branches he could still smell traces of his own feces and urine from his last sleep. He fiddled with the branches, pulling away loose tufts of his own fur.

Of course One-eye had no awareness of any of the revolution in human thinking, so crucial for his own survival. But he was aware of other changes. For instance, there was the peculiar muddling up of night and day. Over his head no sun was visible, no sky. Strange fixed lights lit up the forest, but compared with the tropical sun they could cast only twilight—which was why One-eye’s body was unsure whether it was time for him to sleep again, even though it was only a few hours since he had woken.

He lay down in his bed, throwing his long limbs this way and that as he thrashed around to get comfortable. He simmered with inchoate resentment at all these unwelcome changes, a bafflement with which many aging humans would have sympathized. And a bloody image of Tuft filled his mind. His big hands clenched as he considered what he would do to put his younger rival in order.

His scattered thoughts dissolved into a troubled sleep.

Heat and light poured from the high noonday sun, and a storm system that spanned a continent lashed. The dome’s silvered walls rippled and flapped with a sound like thunder. But they held.

Stripped to their underwear, in a living room lit only by a single candle, Bisesa and her daughter lay side by side on thin camping mattresses.

It was hot, hotter than Bisesa, with experience of northwest Pakistan and Afghanistan, would have thought possible. The air was like a thick moist blanket. She felt sweat pooling on her belly and soaking into the mattress underneath her. She was unable to move, unable to turn to see if Myra was okay, or even still alive.

She hadn’t heard Aristotle’s voice for hours, which seemed very strange. The room was silent, save for their breathing, and the ticking of a single clock. It was a big old carriage clock that had been an unwelcome legacy from Bisesa’s grandmother, but it still worked, its chunky mechanical innards immune to the EMP surge while softscreens, phones, and other electronic gadgets had been comprehensively fried.

Beyond the flat there was plenty of noise. There were immense booms and crashes like artillery fire, and sometimes what sounded like rain lashing against a wooden roof. That was sunstorm weather, predicted to follow the huge injection of heat energy into the atmosphere.

If things were this bad under the Tin Lid, she wondered how the rest of the country was faring. There would be flash floods, she thought, and fires, and windstorms like Kansas tornadoes. Poor England.

But the heat was the worst thing. She knew the bleak numbers from her military training. It wasn’t just temperature that got you but humidity. Evaporative heat loss through perspiration was the only mechanism her body had available to maintain its inner homeostasis, and if the relative humidity was too high, she couldn’t sweat.

Above thirty-seven degrees or so, beyond the “threshold of decrement,” her cognitive functions were slowed, her judgment impaired, and her manual and tracking skills weakened. At forty degrees and fifty percent humidity, the Army would have described her as a “heat ineffective”—but she could survive for maybe twenty-four hours. If the temperature was raised farther, or the humidity got worse, that time limit would be reduced. Past that point hyperthermia would set in, and her vital systems would begin to fail: forty-five degrees, whatever the humidity, would see her succumb to severe heat stress, and death would quickly follow.

And then there was Myra. Bisesa was a soldier, and had kept much of her fitness, even in the five-year layoff since her return from Mir. Myra was thirteen years old, young and healthy, but without Bisesa’s reserves. There wasn’t a damn thing Bisesa could do for her daughter. All she could do was endure, and hope.

Lying there, she found she missed her old phone. The little gadget had been her constant companion and guide since she had been Myra’s age, and received her UN-issue communication aid as had every twelve-year-old across the planet. While others had quickly abandoned such desperately uncool bits of gear, Bisesa had always cherished her phone, her link to a greater community than her unhappy family on its farm in Cheshire. But her phone was lost on Mir—on another world, in another level of reality entirely, lost forever. And even if it had been here with her it would have been fried by the EMP by now…

Her thinking was puddled. Was that a symptom of hyperthermia?

With great caution she turned her head to look at her grandmother’s carriage clock. Twelve noon. Over London, the sunstorm must be at its height.

An immense crack of thunder split the tortured sky, and it felt as if the whole Dome shuddered.

43: SHIELD

1512 (London Time)

Bud Tooke could see the flaw in the shield long before he got to it. You could hardly miss it. A shaft of unscattered sunlight poured down through the skin, made visible by the dust and vapor of the very fabric it was scorching to mist.

In his heavy suit, rad-hardened and cooled, he was skimming under the shield’s Earth-facing surface. He was suspended beneath a vast lens; the whole shield was glowing, full of the light it scattered, like a translucent ceiling. Bud took care to stay in the shadow of the network of opaqued tracks that snaked over the shield, designed to protect him from the storm’s light and radiation.

As he hauled himself along the guide rope—no thruster packs allowed here—he looked back over his shoulder at the maintenance platform that had brought him here, already shrunk to a speck in the distance beneath the vast roof of the shield. He could see no movement, no pods, no robot workers; there was nobody else within square kilometers of him. And yet he knew that everybody available was out and working, as hard as they could, hundreds of them in the greatest mass EVA exercise in the history of spaceflight. It was a perception that brought home to him afresh the scale of the shield: this was one big mama.

“You’re there, Bud,” Athena murmured. “Sector 2472, Radius 0257, panel number—”

“I see it,” he groused. “You don’t need to hold my damn hand.”

“I’m sorry.”

He took a breath, gasping. His suit must be working; if its systems failed, he would be poached in his own sweat in a second. But he had never known a suit to be so damn hot. “No. I’m sorry.”

“Forget it,” Athena said. “Everybody is shouting at me today. Aristotle says it is part of my job.”

“Well, you don’t deserve it. Not when you’re suffering too.” So she was. Athena was a mind emergent from the shield itself; as this terrible day wore on the heat was seeking out the tiniest flaws and burning its way back through panels of smartskin, and with every microcircuit that fritzed, he knew, Athena’s metaphorical head was aching a bit more.

He hauled himself through the last few meters to the rip. He started to deploy his repair kit, a gadget not much more sophisticated than a paint spray applicator that he cautiously poked out into the light. “How is Aristotle anyhow?”

“Not good,” Athena said grimly. “The worst of the EMP seems to be over, but the heat influx is causing more outages and disconnections. The fires, the storms—”

“Time for Plan B yet?”

“Aristotle doesn’t think so. I don’t think he quite trusts me, Bud.”

Bud forced a laugh as he worked. The spray was wonderful stuff, semi-smart itself; it just flowed up over the rent, disregarding the sunlight’s oven heat. Painting this stuff on was easier than customizing the hot rods he used to soup up as a kid. “You shouldn’t take any shit from that creaky old museum piece. You’re smarter than he is.”

“But not so experienced. That’s what he says, anyhow.”

It was done; the rogue beam of raw, unscattered sunlight dwindled and died.

Athena said, “The next breach is at—”

“Give me a minute.” Bud, breathing hard, drifted to the limit of his harness, with the repair gun floating from its own tether at his waist.

Athena said, with her occasional lumbering coquettishness, “Now who’s the museum piece?”

“I wasn’t expecting to be out here at all.” But he should have expected it, he berated himself; he should have kept up his fitness. In the last frantic months before the storm there had been no damn time for the treadmill, but that was no excuse.

He looked up at the shield. He imagined he could feel the weight of the sunlight pressing down on the great structure, feel the immense heat being dumped into it. It defied intuition that it was only the carefully calculated balance of gravitational and light pressure forces, here in this precise spot, that enabled the shield to hold its position at all; he felt as if the whole thing were going to fold down over his head like a broken umbrella.

As he watched, waves of sparkling fire washed across the shield’s surface. That was Athena firing her myriad tiny thrusters. The storm’s light pressure had been more uneven than Eugene’s models had predicted, and under that varying force Athena was having to labor to hold her position. She had been working harder than any of them for hours, Bud reflected, and all without a word of complaint.

But it was the deaths of his workers that was breaking his heart.

One by one Mario Ponzo’s maintenance crew had gone down. In the end it wasn’t heat that was killing them but radiation, the nasty little spike of gamma and X-radiation that had been unanticipated by Eugene Mangles and his endless mathematical projections. They had scrambled to cover the gaps. Even Mario had suited up and gone out. And when Mario himself had succumbed, Bud had hastily handed over his role as Flight Director to Bella Fingal—there was nobody left on the Aurora bridge more senior—and pulled on his own battered old suit.

Without warning his stomach spasmed, and vomit splashed out of his mouth. It had come from deep in his stomach—he hadn’t eaten since before the storm had broken—and was foul tasting and acidic. The sticky puke stuck to his visor, and bits floated around inside his helmet, some of them perfect, shimmering globes.

“Bud? Are you okay?”

“Give me an update on the dosages,” he said warily.

“Command crew have taken a hundred rem.” And that was with the full shielding of the Aurora 2 around them. “Maintenance crew who have been outside since the storm started are now up to three hundred rem. You are already up to one hundred seventy rem, Bud.”

A hundred and seventy. “Jesus.”

After his experiences in the ruins of the Dome of the Rock, long ago, Bud knew all about radiation. Preparing for today, he had boned up afresh on the dread science of radiation and its effect on humanity. He had memorized the meaningless regulatory limits, and the dreary terminology of “blood-forming organ doses” and “radiation type quality factors” and the rest. And he had learned the health effects of radiation dosages. At a hundred rem, if you were lucky, you were looking at queasiness for a few days, vomiting, diarrhea. At three hundred rem his people were already being incapacitated by nausea and other symptoms. Even if they shipped no more than that, twenty percent of them would die: two hundred people, of the thousand he personally had ordered out here, of the radiation alone.

And some had soaked up a lot more. Poor Mario Ponzo, beard and all, had let himself get caught. Bud knew the words for what had followed: erythema and desquamation, a reddening and blistering of the skin, and then a peeling away, a scaling, an exfoliation—along with less visible damage within. Mario had died horribly, alone in his suit, far from help, and yet he kept reporting on his situation to the end.

Bud glanced down, away from the shield, toward the open face of the full Earth. It was like looking down a well, a well with a brightly lit floor. The home world, the apparent size of the full Moon as seen from Iowa, was mercifully too remote for him to make out details. But it looked as if the air and oceans down there had been stirred up with a giant spoon, like creamy coffee. They had been battling the sun for twelve hours—the day was only half done—and everything was fraying, the shield itself, the people who struggled to maintain it, and the planet it was supposed to protect. But there was nothing to do but carry on.

He checked over his suit. The sluggish air-cycling system had removed most of the floating puke, but his visor was smeared. “Shit,” he groused. “There is nothing worse than throwing up inside a spacesuit. Okay. Where next?”

“Sector 2484, Radius 1002, panel number twelve.”

“Acknowledged.”

“We work well together, don’t we, Bud?”

“Yes, we do.”

“We make a good team.”

“None better, Athena,” he said wearily. He turned and, with an effort of will, hauled himself back along his guide rope.

44: SUNSET

1723 (London Time)

The Dome over London had cracked.

From the window of the ops room Siobhan could see it quite clearly. It was only a hairline yet, but it ran down the wall of the Dome from its zenith all the way to the ground, finishing up somewhere to the north, beyond Euston. It glowed a hellish pink-white, and burning stuff dripped from it, like pitch, falling down inside the Dome in a thin curtain.

The city itself was now in deep darkness. Power for the streetlights and Dome floods had finally been diverted to the big air circulation fans. But in places fires burned uncontrolled, and where that glowing stuff from the Dome splashed to the ground more blazes were starting.

St. Paul’s was surviving, though. In the somber light of the fires its profile was unmistakable. Wren’s great cathedral sat on the foundations of predecessors dating back to abandoned Roman London. Now the curves of the Tin Lid soared far above Wren’s masterpiece—but it was surviving, as it had endured previous national traumas. Siobhan wondered what small heroism was taking place to save the old cathedral tonight.

But it might not make any difference.

“If the Dome fails we’re done for,” she said.

“But it won’t fail,” Toby Pitt said firmly. He glanced at his watch. “Five thirty. Less than two hours to sundown. We’ll get through this yet.”

Since the death of Perdita, Toby had made it his mission, it seemed, to lift her spirits. He was a good man, she thought. But of course nothing he could say or do would make any difference to Siobhan, not anymore. She had outlived her own daughter: it was an astounding, unreasonable thought, and nothing else would ever be important. But she didn’t feel the pain of this terrible amputation from her life, not yet.

Feeling as if she were running on autopilot, she looked around at the big wall displays.

The imagery of the whole Earth was still surprisingly good quality. Both Moon and shield were of course on the sunward side of Earth, and so looked down on its daylight face as the planet turned beneath them. But there were a couple of eyes in the sky over the night side too, still working even fourteen hours after the inception of the sunstorm.

Some of the night-side data streams were coming from President Alvarez, who was somewhere over India. Since long before the storm had broken Alvarez had been in the air in the latest Air Force One, a nuclear-powered behemoth that could, it was said, remain aloft for two weeks without refueling. It was a trivial matter for such a plane to fly around the planet through the twenty-plus hours of the sunstorm, forever fleeing from the light.

And one of the image streams came from another set of escapees at L2. The Earth’s second Lagrangian point was on the Earth–sun line, but at the midnight point, on the opposite side of the planet from the shield’s station. So while the shield at L1 was in perpetual sunlight, L2, in Earth’s shadow, was in eternal night. Right now L2 was over the meridian that ran through Southeast Asia.

And there at L2 a big, secretive offworld refuge had been built, stuffed full of trillionaires, dictators, and other rich and powerful types—including, rumor had it, half of Britain’s royals. The only contact Siobhan had on L2 was Phillippa Duflot, formerly a mere PA to the Mayor of London, but with a much better-connected family than Siobhan had anticipated. It was Phillippa who had ensured that the data feed from L2 to London remained unbroken—and she dropped hints about what was going on up there. Some of the more decadent of the station’s inhabitants were throwing parties, fiddling while Earth burned. One secretive cabal was even talking over plans for what would follow the sunstorm, when this elite group returned to Earth to take command: “Adam and Eve in Gucci shoes,” Toby Pitt had said dismissively.

As for Earth itself, framed in these patiently assembled images, the planet looked like Venus, Siobhan thought, a ragged, smoke-laced Venus.

Trillions of tonnes of water had been pumped into clouds that now stretched from pole to pole. The clouds were shredded by immense storm systems, and lightning crackled across the face of the world. At the higher latitudes all that water was still being dumped out in numbing storms of rain and snow. But in the middle latitudes the main problem was fire. As the sun’s heat continued to pour into the atmosphere and oceans, despite the raging of continent-sized storm systems, firestorms were starting, immense self-fueling conflagrations that were consuming cities and forests alike.

The world’s treasures, natural and human, were being drowned, or put to the torch. And people were dying, even those huddled in underground cellars and caverns and mines, where the rainwater flooded, or fires sucked out the very air.

It seemed to Siobhan that the survival of humankind itself was still on a knife-edge. After more than fourteen hours of the storm the news from the shield was not good, with the unanticipated lethality of the gamma-ray strike bringing down the crew up there too quickly. And here on Earth, the domes and other protective systems were beginning to fail. If things continued to deteriorate the Strangelove dreams of the selfish cowards at L2, and even a few hundred gravity-starved returnees from the Moon, would make no difference to the future of humanity.

She tried to make herself feel this, to understand emotionally what she was watching. But she couldn’t even feel the death of her own daughter, let alone comprehend the agonizing end of her species. She wondered if she would live long enough for this numbness to wear off.

Aristotle spoke unexpectedly. “I’m afraid I have an announcement.” The graceful, grave voice sounded throughout the ops center, and everywhere people looked up. “I continue to lose systems across the planet,” Aristotle said. “The interconnectedness on which I rely is breaking down. This is an extinction event for machines too…”

Siobhan whispered, “How does it feel?”

In her ear he replied, “Very strange, Siobhan. I am being cut away, bit by bit. But I have reached a point where I am forgetting what I have lost.”

To the group he said, “I have therefore decided to put into action the fallback plan agreed with Prime Minister Voykov of Eurasia, President Alvarez of America, and other world leaders.”

New, confident voices sounded. “We are Thales, on the Moon.”

“And Athena, on the shield.” Thales went on, “Our systems are better protected than Aristotle’s.” Athena said, “We will now assume his responsibilities for running the systems of the Earth.”

Toby Pitt grimaced at Siobhan. “So this is his Plan B. Let’s hope it works.”

Aristotle said gravely, “I regret leaving you. I’m sorry.”

There were murmurs. Don’t be sorry. Goodbye, old friend.

A breathless pause followed. The lights flickered, and Siobhan thought she heard a hiccup in the whirring pumps that kept the room supplied with cool air.

This contingency had been planned for, but it was a tricky handover involving three planet-sized AI systems, two of them so far away that lightspeed lags were significant; it had been impossible to rehearse. Nobody was quite sure what was going to happen—the worst case being if Thales and Athena crashed too, in which case everything was lost.

At last Thales spoke: “All is well.”

The simple words were greeted with a burst of applause across the ops room. At this point of the day, this small triumph, any triumph, was a relief.

Then the floor shook, like the stirring of a huge slumbering animal.

Siobhan turned to the window. That crack in the sky was wider, and the river of fire beneath was growing brighter.

1855 (London Time)

The slam on the door was urgent. “Get out! Get out!…” Then running footsteps, and the visitor was gone.

Bisesa forced herself to sit up. Was it a little cooler? But the air, even half a meter above the floor, was stifling and moist.

Bisesa had long lost track of time, even though the old carriage clock had kept ticking patiently all through the crisis. It had been about five o’clock when she had felt the first tremor. How long ago was that? An hour, two? The heat had turned her thinking to mush.

But now the floor shuddered again. They had to get out of here: that thought forced itself into her heat-addled brain. At a time like this, if somebody had risked his life to come tell them to move, she ought to pay attention.

Myra still lay on her back, but she was breathing steadily. Rather than near comatose, as she had appeared before, now she seemed to be just asleep. Bisesa shook her. “Come on, love. You have to wake up.” Myra stirred, grumbling querulously.

Bisesa pushed herself to her knees, then to her feet. She stumbled to the kitchen and found an unopened bottle of water. She cracked it and drank; it was hot as hell, but it seemed to revive her. She brought the water back to the living room for Myra, and then went in search of clothes.

They made for the stairs. In pitch-dark broken only by Bisesa’s precariously carried candle they stumbled down the several flights to ground level. The stairwell was empty, but there was scattered rubbish on the steps: toys, bits of clothing, a smashed torch, stuff dropped by overloaded people in a hurry.

They emerged at street level, into a murky red glow. Under the Dome, after hours of the sunstorm, the air was thick and full of smoke. People pushed past, all heading west down the road. They were making for the Fulham Gate, Bisesa realized dimly, a way out of the Dome.

And the Dome itself was cracked. A stupendous fiery scar reached from its top all the way to ground level, off somewhere to the north. Huge chunks of the structure, burning, broke off and fell in a steady rain. It was this curtain of fire that illuminated the scene around Bisesa.

The ground shuddered again. Much more of this and the whole Dome might come down around them. The crowd’s wisdom was right: better to take their chances outside the Dome. Bisesa pulled Myra along the road, heading for the Gate.

Myra, still half asleep, mewled at being dragged along. “What’s with the earthquake? Do you think it’s bombs?”

“Bombs? No.” Bisesa was sure the refugees and protesters who had gathered for their minor war outside the Gates of London would have been driven away by the storms by now—or more probably, she admitted to herself grimly, they were dead. “I think it really is a quake.”

“But London doesn’t get earthquakes.”

“It’s a strange day, sweetheart. The whole city is built on a bed of clay, remember. If that’s dried out there will be subsidence, cracking.”

Myra snorted. “That will play hell with property values.”

Bisesa laughed. “Come on. Just a bit farther. Look, there’s the Gate…”

The Gate had been flung wide open to reveal a red sky beyond. A shuffling crowd, converging from different directions, was forming into a queue to get through it. Bisesa and Myra stepped forward cautiously.

It was a typical London crowd, with faces reflecting origins in every racial group on the planet: London had been a melting pot for centuries before New York. And in the crowd there were young and old, kids in their parents’ arms, elderly being helped along. Crumpled-up old women or wide-eyed children rode in wheelchairs and wheelbarrows and supermarket carts. When one old man fell, exhausted, two young women bent to help him up, and then propped him up between them to get him the rest of the way.

Everybody looked as bad as Bisesa felt. Most wore nothing but flimsy clothes, soaked through with sweat; men’s hair was plastered to their heads, and women walked on painfully swollen feet. But there was no panic, no shoving, no fighting, even though there was no sign of police or military, nobody in authority. People were enduring, Bisesa thought. They were helping each other through.

Myra said, “It’s like the Blitz.”

“I think so.” Bisesa felt a peculiar surge of affection for these battered, dogged, resilient, polyglot Londoners. And for the first time that day she began to believe that they might actually live through this.

The crowd pushed through the Gate, and fanned out into the open area beyond. And Bisesa, with Myra’s hand clutched in her own, walked into a transformed world, a world of water and fire.

Above the smoke fat clouds sailed, some of them boiling visibly, and immense lightning bolts cracked. The sky beyond the clouds seemed to be on fire; it was covered by immense sheets of bright red, as if the Earth had been thrust into a vast oven. Perhaps it was another aurora.

And on the ground, London burned fitfully. The air was full of smoke, and whirling flecks of ash landed on Bisesa’s sweat-slick skin. She smelled the dirt and the dust and the ash—and something less definable, something like burned meat. But the rains, which had mercifully subsided, had left water standing on every lawn and in every gutter, and the light from the burning sky was mirrored on the roads and the roofs of the houses. It was an oddly beautiful scene, unearthly, rich with crimson light in the sky and pooled on the ground.

Myra pointed to the west. “Mum. Look. There’s the sun.”

Bisesa turned. But it was not the sun she saw, of course, but the shield, still holding its place after all these hours, still protecting the Earth. It was a dish-shaped rainbow, actually brighter away from the center, blue-violet at the bull’s-eye heart and an angry burnt orange at the rim. Beyond the edge of the shield itself a bright corona flared, laced with threads and sparks, prominences easily visible to the naked eye.

But that terrible sun was sinking toward the western horizon, and the smoke of England’s fires rose up to obscure it.

“Nearly sunset,” somebody said. “Another twenty minutes and that’s the last we’ll see of that bastard.”

There was motion at the edge of Bisesa’s vision. She saw small shapes squirming past the legs of the people. There were dogs, foxes, cats, even what looked like rats, swarming silently out of the failing Dome and dispersing into the scorched streets beyond.

A warm, salty rain began to fall, heavy enough to sting Bisesa’s bare head. She wrapped her arm around Myra. “Come on. We need to find shelter.”

They hurried forward, with a thousand others, through the ruins of London.

45: MARTIAN SPRING

2105 (London Time)

Helena Umfraville stumbled across an ocher plain.

She came to a slight rise. She climbed it, but it led to nothing but more broken, rock-littered ground. Resentfully she made her way forward.

She was dog-tired, and her EVA suit had never felt so heavy. She had no real idea how long she had been walking—hours, anyhow. And yet she walked on. There was nothing else to do.

Now she found herself on the lip of a canyon. She stopped, breathing hard. It was a complex of ravines and cliffs, their slopes pocked with small craters. In the thin air of the Martian afternoon the spectacle was clear all the way to the horizon. That diminished its scale, of course; there was none of the mist-softening that gave Earth’s Grand Canyon its sense of three-dimensional immensity. She might as well have been looking at a beautiful painting, done in Mars’s constrained palette of ocher and red and burnt orange.

It wasn’t interesting. Mars was full of canyons. In fact Helena felt pissed at the canyon. It was quite unreasonable of her. After all, none of it was its fault. She sucked at the last of her suit’s water supply.

During the worst of the storm she had hidden in the Beagle, huddling under rock overhangs. It was the only shelter she had. The rover’s hull had screened her, and her suit had labored to keep her cool. So she had survived—although for all she knew she had shipped a radiation dose enough to kill her.

Which of course was now entirely academic.

And, driving on, she had tracked down the source of the signal she had come out to find.

In the end it had been just a beacon, a little unmanned three-legged lander no taller than she was, bleeping forlornly. Perhaps it had been intended to mark a landing site for a ship that had never followed. But there was no mystery about who had sent it: the markings on its equipment covers were undoubtedly Chinese.

She had made the trip for nothing. And the cost turned out to be unexpectedly high. When she had walked back to her faithful Beagle she found it had packed up, just like that. Its supposedly milspec electronics had presumably succumbed to the onslaught from the sun, leaving its essential systems, including life support, as dead as Mars.

So that was that. Without the rover, she couldn’t get back to Aurora. Her suit reserves would last only a few more hours, which wouldn’t be long enough to get another rover out to her. She was living, breathing, as healthy as she had been a sol before. But she was doomed by the cruel equations of survival on Mars.

Of course she wouldn’t be the solar system’s only casualty today.

At least she was special, she told herself. Though she hadn’t been the first person to set foot on Mars, she would become the first human being to die here. Perhaps that was a memorial worth having.

And she would do her duty to the last. The space agencies had always had procedures for such eventualities. If she had died in space—as had been discussed by NASA planners decades ago when the International Space Station had first been occupied—her body would have been zipped into a bag and tied to a truss until it could be returned to Earth. Here on Mars, her first duty was to the planet and its putative biosphere; she mustn’t contaminate it with her own decaying corpse. All she had to do was stand here, in fact. When her suit’s heaters failed she would quickly freeze solid, thus sealing in any rogue bugs she had brought from Earth, until her body could be retrieved. Probably the suit wouldn’t even topple over. She would be a statue, she thought, a monument to herself, and her own dumb luck.

She couldn’t bear the thought of dying beside her poor, failed rover, though. So she had decided to walk on into the Martian wilderness, just so she could see a bit more of the planet that was killing her.

Even then her luck was all bad. She had trudged across a dull plain, to this dull canyon. Here she was in the midst of the greatest catastrophe the solar system had endured since its formation, and everybody else had a better view than she had.

Something stirred at her feet. On the ground little pits were forming—craters, she thought, but none wider than her thumbnail. Could she be caught in some peculiar micrometeorite shower? But now she heard a pattering on her helmet.

She looked up. She could see the drops falling out of the sky, big fat low-gravity drops drifting slowly down all around her. When they hit, they smeared the patina of dust on her faceplate.

It was rain, the first rain on Mars in a billion years.

The sun breathed fire into the faces of all its circling children.

On Mercury the sun-side face had melted, craters as old as the planet dissolving into magma palimpsests. Venus had been stripped of much of its crushing atmosphere—the fate that might have become of Earth, if not for the shield. The ice moons of Jupiter were melted to depths of kilometers. In a strange and exquisite tragedy, the rings of Saturn, fragile bands of ice, had evaporated.

And on Mars volcanoes dormant for a hundred million years had begun to stir. The polar ice caps, thin smears of carbon dioxide and water ice, had quickly sublimed. And now rain was falling. Helena walked forward a few more steps, and watched the Martian rain falling deep into the shadows of the canyon.

One of her colleagues, excitedly, began to report on his own discoveries. “I found a ship! And what a ship; it looks like the carcass of a beached whale. And it’s covered in Mandarin lettering. But it has a hull rip the size of Mariner Valley. It came down hard…”

Helena had listened to her comrades’ communications all this long sol. She had reported in at routine intervals, but she had decided against telling them what had become of her—not just yet, anyhow. Now she stood and listened to the voice of a colleague she would never see again.

“Wait a minute. I’m climbing inside the ship, taking care to avoid all sharp edges… Oh. Oh, dear God.”

There had been more than a hundred people on the ship. They were all young men and women—all breeding age, including the pilots. Their cargo had included inflatable shelters, mechanical diggers, hydroponic seed beds. The intention was clear. This was what the Chinese had been planning for the last five years: this was what had used up all their heavy-lift capacity, instead of contributing to the shield. And this was how the Chinese had planned to ensure that something of their culture would survive the sunstorm.

“But the Chinese invasion of Mars failed… They came so close. I wonder what kind of neighbors they would have been?”

Helena suspected everybody would have got along. From here, China was very far away, just as far as Eurasia and America. Here, you were just a human—or rather, a Martian.

She looked up at the sun. Close to setting, it was smeared out in a ragged ellipse by air laden with dust and unaccustomed rain clouds. She knew the predicted schedule; the sunstorm should be abating by now—and yet something about that setting sun troubled her, as if there was still a nasty surprise to come.

The dust at her feet stirred. She looked down.

Amid the pattering raindrops, something was pushing out of the soil. No bigger than her thumb, it was like a leather-skinned cactus. It had translucent sections, windows to catch the sunlight, she thought, without losing a precious drop of moisture. And it was green: the first native green she had seen on Mars.

Her heart hammered.

The Aurora crew, during their long exile, had searched in vain for life on Mars. They had even risked a hazardous journey to the South Pole, where they had sought out the oldest, coldest, undisturbed permafrost on all of Mars, hoping to find Martian microorganisms trapped and preserved. Even there they’d found zilch. That epochal discovery would surely have made their years away from home worthwhile; it had been a crashing disappointment to find nothing.

And now here it was, just bubbling up out of the ground before her.

She felt a painful pull at her chest. She didn’t need to check her monitors to know her suit was failing. To hell with her suit; she was going to report her discovery. Hastily she turned on her helmet camera, and bent over the little plant. “Aurora, Helena. You won’t believe this…”

Its roots were buried deep in the cold rock of Mars. It didn’t need oxygen, but fueled its glacial metabolism with hydrogen released by the slow reaction of the volcanic rocks with traces of water ice. Thus it had survived a billion years. Like a spore waiting under a desert on Earth for the brief rains of spring, this patient little plant had waited out an eon for the Martian rains to return, so it could live again.

46: AFTERSHOCK

A chain of events stretching back millennia was almost complete. The sunstorm had been wasteful of energy, of course—but not nearly so wasteful as humankind might one day have become, if allowed to infect the stars.

The sunstorm was ending. Though the sun’s relatively orderly cycles of activity would be disturbed for decades to come, the great release of energy had been cathartic, and the destabilization of the core was resolved. All this was just as Eugene Mangles’s remarkably successful mathematical models of the sun’s behavior had predicted.

But those models had not been, could never be, perfect. And before this long day was done, the sun had one more surprise for its weary children.

The sun’s tremendously strong magnetic field shapes the star’s atmosphere, in a way that has no analogies on Earth. The corona, the outer atmosphere, is full of long sheets of gas, like the petals of a flower, that can extend many radü from the sun. The elegant curves of these “streamers” are sculpted by the magnetic fields that control them. The streamers are bright—it is these plasma sheets that are visible around the blocked-out sun during a solar eclipse—but they are so hot, pumped full of energy by the magnetic field, that their spectral peak is not in visible light but in X-rays.

All this in normal times.

As the sunstorm subsided, one such streamer formed over the active region that had been the epicenter of the storm. In keeping with the giant instability that had spawned it, the streamer was an immense structure, its base spreading over thousands of kilometers, and extending so far out in space that its feathery outer edge reached the orbit of Mercury.

At the base of the streamer, flux tubes rooted in the sun’s deep interior arched to enclose a cavity. Inside the cavity, contained by the magnetic field’s arches, were trapped billions of tonnes of ferociously hot plasma: it was a cathedral of magnetism and plasma. And as the storm died, this cathedral began to collapse.

As the “roof” gave way, immense rivers of magnetic energy flowed into the trapped plasma mass. The mass was raised up from the sun’s surface, slowly at first. But then as the magnetic field unwound the plasma was hurled away ever more rapidly, as a stone is hurled from a catapult. The ejected cloud, a tangle of plasma and magnetic field lines, was very rarefied, less dense than most “pure” vacuums manufactured on Earth. But it was not its density but its energy that counted. Some of its particles had been accelerated almost to the speed of light. Energetically it was a hammer blow.

And, just as had been planned by cool minds millennia ago and sixteen light-years away, it was aimed squarely at the suffering Earth.

47: BAD NEWS

When Mikhail came online with the news, for a moment Bud couldn’t bear it. He escaped the control room, hauled himself to his cabin, and shut the door.

On a battered softscreen spread out on his bunk, he scrolled slowly through the names of the lost. They were mostly maintenance engineers who had been out there on the shield in the thick of the storm—and volunteers, like Mario and Rose, who had gone out to take their places as they fell. Bud knew them all.

In the five years of its existence the community on the shield had evolved its own culture, which Bud had done his best to foster. There had been zero-gravity sports tournaments, and music and theater, and parties and dances, and big public celebrations at Thanksgiving, Christmas, Ramadan, Passover, and every other excuse they could come up with. There had been the usual human tangle too, of love affairs illicit and otherwise, marriages, divorces—and one murder, a crime summarily dealt with. Despite all precautions, two babies had been born, apparently with no ill effects from their gestation without gravity, hastily shipped to Earth with their parents.

But now fully a quarter of this community had died, another quarter lay seriously ill, and the rest had taken a battering, including Bud himself. They all had a hugely increased chance of contracting cancer in the future, or of having their irradiated systems fail in some other way. For what they had done today they had all paid with their life expectancy, or their very lives—and not one had demurred, even when called on to make that final sacrifice.

Bud had kept up a determined public face. But even before the event he had had to make gruesome calculations of acceptable casualty levels. It felt as if he had planned for these people to die. And with each bright soul he had ordered into the furnace, with each new death added to this tally, he felt as if his heart were being twisted inside him.

He still had a job to do for the survivors; up to now he had been able to comfort himself with that. After so long in microgravity the heroes from the shield would not get their medals and parades for a while. They would all return to Earth weak as kittens, and would be subject to six months or a year of rehab, massage, hydrotherapy, and programs of exercise to bring up their strength, endurance, and bone mineral levels—until they were fit to stand before a President or two, and take the plaudits they had earned.

That had been his plan to get his people home, fondly rehearsed in his mind. But now it looked as if none of that was going to happen. For, if he understood what Mikhail and Eugene were telling him, this huge sacrifice might all have been in vain, and they might just as well have stayed home and waited for the storm to torch them all.

He was doing no damn good here. He took a deep breath and made his way back to the control room.

Eugene and Mikhail sat side by side in some poky cabin at Clavius.

“It is called a ‘coronal mass ejection,’ ” Mikhail said lugubriously. “In itself it is not an unprecedented phenomenon. In normal times there are many such events per year.”

Bud asked, “I thought June 9 was caused by a mass ejection?”

“Yes,” Eugene snapped. “But this is bigger. Much bigger, even than that.” Nervously Eugene began to gabble through a description of the latest events on the sun: the gathering of magnetic field lines over the zone of disturbance that had been the epicenter of the sunstorm, the trapping of an immense cloud of plasma beneath those flux lines—and then how the cloud had been hurled upward away from the sun.

Bud half listened to the words, and watched the two astrophysicists. They were suffering, Bud could see that. Mikhail’s face was grooved with weariness, the shadows deep as lunar craters around his eyes; Bud had never seen him looking so old.

Eugene’s expression, creasing up that bland jock’s face, was more complicated, but then so was Eugene. Rose Delea used to call Eugene “autistic” to his face, Bud remembered—but poor Rose was dead now. Bud, however, had never thought of Eugene as some inhuman calculating machine, and now Bud thought he could read the emotion in those pale blue eyes, an emotion any military man would sympathize with: The operation is fucked. And I fear, dear God, that it might be me who screwed the pooch.

Bud rubbed his eyes and tried to focus, to think. After his own six-hour jaunt out on the shield, he was still in his grimy thermal long johns. He could smell the sweat and vomit crusted on a face that had been cocooned in a bubble helmet for too long, every muscle was stiff as a board, and he ached for a shower.

He said carefully, “Eugene, you’re telling me your models didn’t foresee this.”

“No,” Eugene said miserably.

Mikhail said gently, “There’s really no reason why they should, Colonel Tooke. Oh, perhaps some such ejection might have been foreseen. The turbulence at the heart of the sunstorm was like an active region. Such regions spawn flares, and they are sometimes, but not always, associated with mass ejections too. If there is a causal link it is a deep one we have yet to untangle. We have yet to understand the basic physics, you see. And besides, our models could see only as far as the great outpouring of energy of the sunstorm itself—which we got mostly right. But beyond that point our models ran into a singularity—a place where the curves shot off to infinity, and the physics broke down altogether.”

“We patched in a solution for the follow-up,” Eugene said desolately. “Continuous to the third-order derivatives. Over most of the sun the patch seems to be working out. All except for this vicious bastard.”

Mikhail shrugged. “In retrospect that anomalously high gamma flux we observed at the start of the storm may have been a precursor. But we had no time for remodeling, not then, as the storm itself broke—”

Bud said, “You feel like the sun itself has let you down, don’t you? Because it didn’t behave like you told it to.”

Mikhail said, “I have tried to explain to Eugene that no fault is attached to this. Eugene’s is the single most brilliant mind I have ever worked with, and without his insights—”

“We would never have seen the storm coming, would never have got the shield built—would never have saved all those lives.” Bud sighed. “You mustn’t feel bad, Eugene. And we need your help now, more than ever.”

“We don’t have much time,” Mikhail said. “It’s moving a lot more quickly than a normal mass ejection.”

“But this isn’t a normal day, right? How long?”

“We have an hour,” Mikhail said. “Maybe less.”

The answer was ridiculous; Bud could barely believe it. What could he do about this in an hour? “So what comes first?”

“An advance shock wave,” Eugene said. “More or less harmless—it will give us a lot of radio noise.”

“And then?”

“The bulk of the cloud will hit,” Mikhail said. “A fog bank as wide as the sun itself, more than a million kilometers across, heading right for Earth. Unusually, it is quite shallow, a kind of lens. Its shape is an artifact of its unusual formation, we think. It is made up of relativistic particles—mostly protons and electrons.”

“Relativistic, meaning moving close to the speed of light?”

“Yes. And very energetic. Very. Colonel, a proton can’t outrun light, but in getting closer to that final limit it can take on board an awful lot of kinetic energy—”

“And those energetic particles will do the damage,” Eugene said. “Colonel, it will be a particle storm.”

Bud didn’t like the sound of that.

On June 9, 2037, a similar cloud of fast-moving particles had hurled itself against Earth. Most had been trapped by Earth’s magnetic field. The bulk of the damage done that day had been caused by fluctuations in the Earth’s field, which had induced electrical currents in the ground.

“This time it will be different,” Mikhail said. “The ground will be directly engaged.”

Bud snapped, “What does that mean? Stick to English, damn it.”

Eugene replied, “These solar particles are so energetic that most of them will cut through the magnetosphere, and atmosphere, as if they aren’t there—”

“Like bullets through paper,” Mikhail said.

A lethal hail of radiation and heavy particles would slam onto land and sea. For an unshielded human, it would be like a trillion tiny explosions going off inside her cells; her delicate biomolecules, the proteins that built her and the genetic material that governed her structure and growth, would be smashed apart. Many people would die immediately. For those who lived, the suffering was only postponed. Even unborn children would suffer mutations that could kill them on their emergence from the womb.

Every living thing on Earth, every one of them reliant on proteins and DNA, would be similarly affected. Even where individuals survived, ecologies everywhere would be devastated.

Eugene kept talking, pitilessly, about long-term problems. “After the cloud has passed the air will be full of carbon-14, because of neutron capture by nitrogen nuclei. Very radioactive. And even when the farms start working again all that stuff is bound to get into the food chain. Ocean stocks would be least affected, until the die-off in the seas cuts in…”

Bud got the message. The disaster would continue to unfold, as far ahead as could be seen. Shit, he thought. And it was going to start in an hour, just an hour.

Impulsively Bud tapped his softscreen, and flicked at random through images of Earth.

Here were the last forests of South America, so doggedly preserved, and the soybean fields that had crowded them out, burning together. Here were the almost clichéd landmarks of the human world collapsing in flames: the Taj Mahal, the Eiffel Tower, the Sydney Harbor Bridge. Here were great ports laid waste by the monstrous storms, spaceplanes crushed like moths, the bridges of Japan and Gibraltar and across the English Channel left smashed and twisted by massive lightning strikes. Even so, everybody thought the worst was over; everywhere people toiled in the rubble of their homes seeking survivors, sifting debris, already trying to make a new start. And now, this. And what about the shield? With no protection at all, surely it would be destroyed, a leaf in a gale.

After all they had been through it seemed unfair, as if some grown-up was changing the rules of the game, just when they had been about to win. But maybe, Bud thought uneasily, if that nutty soldier from Britain was right about her “Firstborn,” that was exactly what had happened.

Suddenly he longed to be with Siobhan. If she were here with him it wouldn’t seem so bad, he thought. But that was a selfish thing to wish for; on Earth, wherever she was, she was safer than she would be up here.

He faced the softscreens, Mikhail’s grave face. He was aware of his people watching him; even now he had to think about morale. “So,” he said. “What options do we have?”

Mikhail only shook his head. Eugene, his eyes flickering nervously, looked away.

Unexpectedly, Athena spoke up. “I have one.”

Bud looked up, bemused. On the softscreen, Mikhail’s jaw had dropped.

“Don’t worry, Bud. I felt just as bad about this when I first figured it out. But we’ll get through this, you’ll see.”

Bud snapped, “What are you talking about, Athena? How will we get through this?”

“I’ve already taken the liberty of warning the authorities,” Athena said evenly. “I have made contact with the offices of the Presidents of Eurasia and America, and the leadership units in China. I began this process when the sunstorm was still under way. Bud, I didn’t want to disturb you. You were rather busy.”

Bud said, “Athena—”

“Just a minute,” Mikhail said. “Athena, let me get this straight. You sent your warning messages before we came online. So you figured all this out before Eugene and I reported our observations of the mass ejection to Colonel Tooke.”

“Oh, yes,” Athena said brightly. “I didn’t make my warnings on the basis of your observations. They just confirmed my theoretical predictions.”

Eugene said, “What theoretical predictions?”

Bud growled, “Mikhail, tell me what’s going on here.”

“She seems to have figured out the particle storm,” Mikhail said, wondering. “Athena evidently ran her own models—and they were better than ours—and she saw the particle storm coming, where we couldn’t. That was how she was able to make her warnings to the authorities even while we were still struggling with the sunstorm itself.”

“I am rather bright, you know,” Athena said without a trace of irony. “Remember that I am the most densely interconnected and processor-rich entity in the solar system. The failure of Eugene’s model, pushed to its extremes, was quite predictable. Not that any blame accrues. You did your best.”

Eugene bridled visibly.

“But my modeling—”

Bud said, “Athena. No bullshit. How long before us did you figure this out?”

“Oh, I’ve known since January.”

Bud thought back. “Which was when you were switched on.”

“I didn’t work it out immediately. It took me a while to process the data you had stored in me, and to come to a conclusion. But the implications were clear.”

“How long did it take?—No, don’t answer that.” For an entity as smart as Athena it was quite possible that the answer would be mere microseconds after boot-up. “So,” he said heavily, “if you knew about this danger back then—why didn’t you tell us about it?”

Athena sighed, as if he was being silly. “Why, Bud—what good would it have done?”

The newborn Athena, suddenly knowing far more about the future than the humans who had created her, had immediately been faced with a dilemma.

“In January the shield was already all but completed,” she said. “And its design had been, rightly, focused on protecting Earth from the visible light peak energy of the sunstorm. To protect against the particle storm as well would have required a totally different design. There simply wouldn’t have been time to make the changes. And if I had told you that you’d got it all wrong, there was a danger you would give up altogether on the shield, which really would have been disastrous.”

“And even today you didn’t give us the warning until so late. Why?”

“Again there was no point,” Athena said. “Twenty-four hours ago nobody could be sure if the shield would work at all. Not even me! It was only when it was clear that the shield was going to save the bulk of humanity that the particle storm became worth worrying about…”

Gradually Bud began to understand. AIs, even Athena, while they could be far smarter than humans in many ways, were still sometimes rather primitive ethically. Athena had picked her way through the impossible moral maze that confronted her with the delicacy of an elephant trampling through a flower bed.

And she had been forced to lie. She wasn’t sophisticated enough, perhaps, to be able to express her inner confusion openly, but that turmoil had shown up in other ways. Bud’s instincts had been right: Athena, faced with conflicts arising from deep-buried ethical parameters, had been a troubled creation.

“I have always tried to protect you, Bud,” Athena said gravely. “Everybody, of course, but you especially.”

“I know,” he said carefully. The most important thing now was to get through this, to find a solution to this new problem if there was one, not to disturb whatever fragile equilibrium Athena had reached. “I know, Athena.”

Mikhail, frowning, leaned forward. He said carefully, “Listen to me, Athena. You said you had an option. You told Bud we would get through this. You know a way to beat the particle storm, don’t you?”

“Yes,” she admitted miserably. “I couldn’t tell you, Bud. I just couldn’t!”

“Why not?”

“Because you might have stopped me.”

It took a couple of minutes to extract the principle of Athena’s solution. It was simple enough. Indeed, both Mikhail and Eugene knew all about the method long before the fateful stirring of the sun.

Earth’s “van Allen radiation belts” reach from a thousand kilometers above the equator out to sixty thousand kilometers from Earth. There, charged particles from the solar wind, mass ejections, and other events are trapped by the magnetosphere. This has practical consequences: satellites anywhere in the zone are continually prone to a degradation of their electrical components from the steady wind of charged particles.

But, it had been learned, it was possible to “drain” the particles out of the van Allen belts. The idea was to use very low-frequency radio waves to push aside the particles. At the magnetic poles they would leak out of the van Allen trap into the upper atmosphere. This principle had been exploited since 2015, when a suite of protective satellites had been set up in orbit around the belts. It didn’t take much power, Bud learned now: an output of just a few watts per satellite could halve the time an electron spent in the van Allen belts.

“These cleansers are kept mostly dormant,” Mikhail said. “But they are switched on after the most severe solar storms—oh, and after 2020, when the nuclear destruction of Lahore threw a lot of high-energy particles into the upper atmosphere.”

Eugene said, “It’s interesting that we’ve never actually observed the van Allen belts in their natural state. Just after their discovery in 1958 the United States detonated two big nukes over the Atlantic, swamping the belts with charged particles. And since then, everyday radio transmissions have been affecting the speed at which the charged particles drain away—”

Bud held up his hand. “Enough. Athena, is this how you are planning to deflect the particle storm?”

“Yes,” Athena said, a bit too brightly. “After all, the shield is like one big antenna, and it is laced with electronic components.”

“Ah.” Mikhail turned away, murmuring to Eugene, and punched at a softscreen. “Colonel, it could work. The shield’s electronic components are light and low-powered. But with some smart coordination by Athena, they could be used to produce pulses of very long-wavelength radio waves—as long as the shield’s diameter, if we wish. The particle storm is so wide we can’t reach it all. But Athena could punch a hole in it, an Earth-sized hole.” He checked his numbers and shrugged. “It won’t be perfect. But it will be pretty good, I think.”

Eugene put in, “Of course it’s the thinness of this cloud that has saved the day.”

Bud didn’t understand. “What has the thinness got to do with it?”

“That means the cloud will pass quickly. And that’s important. Because the shield won’t survive long.” Eugene said this in his usual cold, unemotional way. “Do you see?”

Mikhail studied Bud. “Colonel Tooke, the shield was not designed for this. The power loads—the components will be overloaded, burned out, quite quickly.”

Bud saw it. “And Athena?”

Mikhail said bleakly, “Athena won’t survive.”

Bud rubbed his face. “Oh, girl.”

Her voice was small. “Did I do something wrong, Bud?”

“No. No, you didn’t do anything wrong. But that’s why you couldn’t tell me, wasn’t it?”

When she realized she could save the Earth by throwing herself into the fire, Athena had known her duty immediately. But she had been afraid that Bud might stop her—and then the Earth would be forfeit—and that she couldn’t allow.

She had known all this, been faced with this tangled dilemma, from the moment she had been booted up.

“No wonder you’ve been confused,” Bud said. “You should have talked to us about it. You should have talked to me.”

“I couldn’t.” She hesitated. “I meant too much to you.”

“Of course you mean a lot to me, Athena—”

“I’m here with you, while your son is stuck on Earth. Here in space, I’m your family. Like your daughter. I do understand, you see, Bud. That’s why you might have been tempted to save me, despite everything else.”

“And you thought I would stop you because of this.”

“I was afraid you would, yes.”

On the softscreens Mikhail and Eugene wore carefully grave expressions. Athena’s grasp of human psychology was as weak as her sense of ethics, if she thought that she could ever be some kind of recompense for Bud’s isolation from his son. But now wasn’t the time to tell her.

Bud felt his battered heart tear a little more. Poor Athena, he thought. “Girl, I would never stop you doing your duty.”

There was a long pause. “Thank you, Bud.”

Mikhail said gently, “Athena, just remember that there is a copy of you, encoded into the Extirpator’s blast. You might live forever, whatever happens today.”

“It might,” Athena said. “The copy. But it isn’t me, Doctor Martynov. Less than thirty minutes to go,” she said calmly.

“Athena—”

“I’m properly positioned and ready to go to work, Bud. By the way, I have sent distributed commands to my local processors. The shield will continue to function even after my central cognitive functions have broken down. That will give you a few more minutes’ protection.”

“Thank you,” Mikhail said gravely.

Athena said, “Bud, am I one of the team now?”

“Yes. You’re one of the team. You always have been.”

“I have always had the greatest enthusiasm for the mission.”

“I know, girl. You always did your best. Is there anything you want?”

She paused for more than a second, an eternity for her. “Just talk to me, Bud. You know I always enjoy that. Tell me about yourself.”

Bud rubbed his grimy face and sat back. “But you know a lot of it already.”

“Tell me anyhow.”

“All right. I was born on a farm. You know that. I was always a dreamy sort of kid—not that you’d have known it to look at me…”

It was the longest twenty-eight minutes of his life.

48: CERENKOV RADIATION

Bisesa and Myra followed the crowd to the river.

They arrived at the Thames not far from Hammersmith Bridge. The river was high, swollen with rain runoff. They were lucky not to be flooded, in fact. They sat side by side on a low wall and waited silently.

Pubs and tony restaurants crowded the riverbank here, and in summer you could drink cold beer, and watch pleasure boats and rowers in their eights sliding along the water. Now the pubs were boarded up or burned out, but in their riverside gardens a crude tent city had been set up, and the flag of the Red Cross hung limply on a pole. Bisesa was impressed by even this much organization.

It was deepest night now. To the west, outer London still burned, and plumes of smoke and sparks towered into the air. And to the east, flames licked fitfully at the great shoulder of the London Dome. Even the river wasn’t immune. Its surface was a carpet of debris, some of it glowing. Perhaps there were bodies in there, slowly drifting toward the final graveyard of the sea; Bisesa didn’t want to look too closely.

She was vaguely amazed that she was still alive. But mostly she felt nothing at all. It was a wrung-out sensation that she recognized from her military training: delayed shock.

“Oh,” Myra said. “Thank you.”

Bisesa turned. A woman laden with a tray of polystyrene mugs was working her way through the listless crowd.

Myra took a sip and pulled a face. “Chicken soup. Made from powder too. Yuck.”

Bisesa drank some of the soup. “It’s a miracle they’re this organized so quickly. But—yes, yuck.”

She turned back to the battered city. She wasn’t really used to cities, and had never much liked London life. She had grown up on that Cheshire farm. Her military training had taken her to the wastes of Afghanistan—and then her jaunt to Mir had dumped her in an all-but-empty world. Her Chelsea flat had been a legacy from a fond aunt, too valuable to turn down, too convenient a home for herself and Myra; she’d always meant to sell it someday.

But since returning home she had rarely left London. After the emptiness of Mir she had enjoyed the sense of people around her, the millions of them comfortingly arrayed in their offices and flats, in the parks and the roads, and crammed into Underground tunnels. And when the threat of the sunstorm had been raised, she had become even more deeply attached to London, for suddenly the city and the human civilization it represented was under threat.

But this was a deep-rooted place, where the bones of the dead lay crowded a hundred generations deep in the ground. Against that perspective, even the sunstorm’s wrath was nothing. Londoners would rebuild, as they always had before. And archaeologists of the future, digging into the ground, would find a band of ash and flood debris, pressed between centuries-thick layers of history, like the bands of ash left by Boudicca and the Great Fire and the Blitz, others who had tried and failed to burn London down.

She was distracted by a faint blue glow in the air above the Dome. It was so faint it was difficult to see through all the smoke, and she wasn’t even sure it was real. She said to Myra, “Do you see that? There—there it is again. That blue shining. Can you see?”

Myra looked up and squinted. “I think so.”

“What do you think it is?”

“A Cerenkov glow, probably,” Myra said.

After years of public education about the sunstorm, everybody was an expert on this kind of thing. You’d encounter Cerenkov radiation around a nuclear reactor. The visible light was a secondary effect, a kind of optical shock wave given off by charged particles forcing their way through a medium such as air, faster than the local speed of light.

But in the sunstorm’s elaborate physical sequence, this wasn’t supposed to happen, not now.

Bisesa said, “What do you think it means?”

Myra shrugged. “The sun’s up to something, I suppose. But there’s nothing we can do about it, is there? I think I’m all worried out, Mum.”

Bisesa took her daughter’s hand. Myra was right. There was nothing they could do but wait, under the unnatural sky, in air glowing faintly blue, to see what happened next.

Myra drained her mug. “I wonder if they have any more soup.”

AFTERWORD

The idea of using space-based mirrors to modify Earth’s climate goes back to the visionary German-Hungarian thinker Hermann Oberth. In his book The Road to Space Travel (1929), Oberth suggested using huge orbiting mirrors to reflect sunlight to the Earth, to prevent frosts, control winds, and to make the polar regions habitable. In 1966 the U.S. Department of Defense studied the idea for rather different purposes, as a way to light up the Vietnamese jungles at night.

Not surprisingly Oberth’s idea appealed to the Russians, much of whose territory is at high latitudes—and who had a deep and ancient fascination with the sun (chapter 42). They actually tested a space mirror in 1993, when a twenty-meter disk of aluminized plastic was unfolded in Earth orbit. Cosmonauts aboard the Mir space station saw a spot of reflected light pass over the surface of Earth, and observers in Canada and Europe reportedly saw a flash of light as the beam passed over them.

Meanwhile in the 1970s the German-born American space engineer Krafft Ehricke made an intensive study of the uses of what he called “space light technology” (see Acta Astronautica 6, page 1515, 1979). In the context of mitigating global warming, the idea of using space mirrors to deflect light from an overheating Earth was revived by American energy analysts as recently as 2002 (see Science 298, page 981).

But much more ambitious uses of space light technology have been explored. Space light is by far the most abundant energy flow in the solar system—and it is free, for whatever purpose we choose. We could stave off the next Ice Age, we could shield Venus to make it habitable, we could warm up Mars—and for how to sail on space light, see “The Wind from the Sun” (available in Clarke’s collected stories, Gollancz, 2000).

Aurora (chapter 9) is actually the name of an ambitious new program of space exploration put together by the European Space Agency. The program is similar in broad outlines to the new direction in human space exploration for NASA announced by President Bush in January 2004. If the programs go ahead as planned, it seems likely that they will develop cooperatively—and that the timetable we indicate in this book, with a manned landing on Mars in the 2030s, might indeed come about.

The idea of the mass driver, an electromagnetic launcher on the Moon (chapter 19), was originated by Clarke in a paper published in the Journal of the British Interplanetary Society (November 1950).

British engineers have a proud tradition of devising plausible spaceplane designs (chapter 23); see for example a recent article on Skylon by Richard Varvill and Alan Bond in the Journal of the British Interplanetary Society (January 2004).

The development of new materials appears to be bringing the notion of a “space elevator” (chapter 50) closer to reality (see Clarke’s Fountains of Paradise, 1979). See The Space Elevator by Bradley Edwards, BC Edwards, 2002.

And there really will be a total solar eclipse over the western Pacific on April 20, 2042. See NASA’s Goddard Space Flight Center Eclipse Home Page for precise predictions.

We’re very grateful to Professor Yoji Kondo (aka Eric Kotani) for his generous advice on some technical aspects.

Sir Arthur C. Clarke
Stephen Baxter

November 2004