Mechanisms towered about Dimity and Vaemar. Dimity had, with Vaemar's help, improvised a breathing mask, which she hoped would keep out the smell of any tree-of-life, from the tatters of what had been the top part of her suit, and sealed the rents in the rest as well as she might with an all-purpose repair gel from Chorth-Captain's belt. They had obtained a light from the same source. Tracking the Protector by the pain it was radiating had brought them this far.
"Fusion toroids," she said, pointing. "The energy needed to move this between stars must have been vast."
"I am glad our kinds did not know too much about such energies in the past," said Vaemar. "Think of a war fought with bodies like this as missiles."
Something, too fast for human eyes to see clearly, scuttled away in the dark above them. "The Protector," said Dimity. "Why doesn't it attack?"
"It was a Protector," said Vaemar, "but I do not think it was the same one. Dimity, we have been too optimistic, I think. I do not think we have accounted for all the newly awakened Protectors. Perhaps its task is to watch us and report."
They came to an opening into a vast cavern, filled with machinery.
Vaemar stood unmoving for a moment, then he said, "There are . . . vibrations in the air . . . perhaps you cannot sense them . . . which tells me these motors may not be dead."
"After scores or hundreds of thousands of years? Surely not?"
"Look at the cavities in the roof," said Vaemar. "They appear to have been artificially dug."
"Yes."
"Except during brief eclipses, half the external surface of this body is always in sunlight, half in the darkness and cold of space. The temperature differentials on the surface must be very large. It is a problem and an opportunity in all space-engineering."
"Yes. I see what you mean. That would give unlimited electrical power for tunnelling robots. They could extract and refine fuel."
"It would not, perhaps, take much to keep the engines simply ticking over."
"Would Protectors think like that?"
"I cannot know how Protectors would think. They are more like you than me. But I sense there is power here. This asteroid was overlooked for mining because its metallic content is relatively low. But I would guess it was metal-rich when the Protectors chose to make it a spaceship. I guess some automated or natural variety of mining worm has been tunnelling and mining in it for a long time."
"A machine refining its own ore and making its own replacement parts," said Dimity. "We have nothing outside fiction that can do that for so long or on such a scale. Self-sustaining machinery, processes still carrying on after a million years. And we have no information that Cybernetics was a Protector talent."
"Obviously, they could have set themselves to acquire such a talent. Dimity, this gives us a glimpse of what mature Protector technology can do! I do not like it. . . . And look! There are lights. They could be solar-powered engines ticking over. Or powered by long-lived fission or fusion processes. Doing essential maintenance, ready to set off a fusion reaction when needed. There are many ways hydrogen could be collected and stored, for example. Or perhaps it has been completely closed down and our Protector and Chorth-Captain have reactivated it."
"It is as well, as you say," said Dimity, "that this moon was not properly explored before the end of the war. It could have been a super-weapon."
"It still could be. I do not know if we should approach anything critical too closely. It may provoke a response."
"I think we have to provoke a response. The status quo does not favor us."
Dimity stepped forward cautiously. She gave a cry of fear and surprise. Vaemar leapt, grabbed her with one arm and pulled her back. Then he advanced cautiously and pointed. "Nothing to fear too much. An active kzin gravity-sled. Heavy-duty Naval model. Chorth-captain must have brought it here. We can avoid its field."
"I am sorry. I am a little rattled. You can handle one, Vaemar?"
"Of course. I have flown one since I was a kit. It was one of the first things Honored Step-Sire Raargh bought when we were living in the farm country."
"Then let us not avoid it. Let us use it."
"To fly on? There is not much space for that."
"To fly on and to fight with. Do you think the Protectors would let us use it? We could do great damage if we could fly. I am sure they would try to stop us."
"Dimity, I think the God, whichever one has dominion here, has been good to us. You will have to move very quickly. I will board the sled. You will take the copilot's seat and hang on for your life, and pray that these Protectors still think like Morlock Breeders, jumping down on their enemies when they see us escaping. Now!"
Vaemar and Dimity leapt into the sled. From above, two Protectors sprang. As they did so, Vaemar's claws flashed at the sled's controls, flinging its motor into maximum reverse flux. The Protectors, directly above it, were flung straight up. One smashed into the machinery above them, and stuck among it, the other, as though swimming through air, reached the edge of the field and fell onto the sled. It clung with one hand. Vaemar had time for one slash at the hand, removing three fingers and reducing its power of purchase. Desperately he continued to slash at the leathery arm and snapping beak with the w'tsai and his claws. Dimity grabbed the flight-controls of the sled. They skimmed back along the corridor as Vaemar finally cut the Protector's grip. It changed hands. Vaemar grabbed the controls and stopped the sled, keeping the field focused on the Protector. Dimity screamed in its ear and it let go. It flew upwards, seemed to grow smaller and vanished into the blackness above.
"I hope it ends up at the center of the moon," said Vaemar as they flew back into the first chamber. "Half a mile from any surface. I don't think I killed it, but that will give us time, I hope, to do some real damage. If it was the last Protector. We will have to hope it was. But we cannot continue sticking our noses into the cave, unarmed, in the hope more will come out. We have been lucky so far."
Then he asked: "Why did you make that noise? Were you what humans call terrified? Panicked?"
"In the caves the Morlocks must have evolved and enhanced every nonvisual sense," Dimity said. "Particularly hearing. I thought its hearing would be specially sensitive. Sensitive enough to use against it. I wondered why the other Protector did not leap out of the Sinclair field instantly instead of pausing while the field killed it. Chorth-Captain had screamed as he pushed it in, and I think that stunned it momentarily. They must have evolved in the caves to hear the slightest sound—the rustling of insectoids, the tiny bubbling of water's meniscus rising in grains of mud. Evolution towards hearing microsounds. But with never a need to evolve a defense against too much sound. I realized that just now."
"Dimity, you do not disappoint. Now what?"
"We can get away and do real damage at the same time."
"How?"
"The gig has a gravity-motor."
"Yes.
"And a reaction drive."
"So I saw when we came here."
"I do not need to draw you a diagram, then?"
Humans who had spoken so to kzinti before had not lived long to regret their insolence. But Vaemar sprang to the ship, Dimity following.
"We still cannot get out," said Vaemar, as the door closed behind them. Chorth-Captain's key had worked but he punched in an electronic lock as well. Both Vaemar and Dimity had noted the locking and unlocking sequence earlier. "You must bear with me with patience here," said Vaemar. "No monkey-rattling . . . Dimity is not rattled any more?"
"At least we have a weapon," said Dimity. "Let us use it."
"Danger?"
"Hero!"
"Urrr!"
The controls were built in duplicate, in sizes to be used by either Protector or kzinti hands, and Protector hands were very similar to human. As Dimity cut in the gravity-motor, thrusting it downwards, Vaemar fired the reaction-drive. Incandescent plasma gas roared out. The ship shook, but remained balanced between the two forces.
A second was enough. At a gesture from Vaemar they killed the two drives together. Cautiously, they cleared a viewport. Nothing could be seen but blackness, with flames and points and bars of red-hot wreckage fading in it. Even with a powerful searchlight they could make out no more through the smoke for some time. When it cleared somewhat, all that they could see of the inside of the Hollow Moon about them was a charred, melted, ruin.
"We have done it, Dimity!" said Vaemar. "We have killed at least five Protectors, though they took our weapons! Urrr!" A snarl of triumph rose in his throat.
Dimity knew instinctively not to interrupt the young kzin's rejoicing too soon. Analyzing this knowledge, as she always analyzed her reactions, she realized they could not have done what they did had there not been a psi bond of some sort between them. It did not surprise her greatly. Vaemar's Ziirgah sense was a rudimentary form of proto-telepathy which most male kzinti possessed and she knew her own brainwaves were abnormal in several ways. They had acted and planned together almost instantaneously and partly without being aware of the fact.
"Now it is a matter of getting out," she said at length. "The hatch above us is still closed."
Vaemar turned to the control panel again.
"In the absence of Protectors I think I can open it from here," he said. "I need but a little time to study the controls. Normal procedure for a ship like this when leaving a space station is to rise on the gravity motor when the lower hatch is opened, have that close behind us and then open the upper hatch. For obvious reasons both hatches cannot be opened together."
"We can do that from here?"
Vaemar operated a set of switches, watching lights sliding across a screen
"Yes," he said. "And I find that disturbing. It suggests the mechanisms of this installation are less damaged than they might be. I hoped to blast our way out with lasers or armor-piercing shells." He gestured at another control panel. "I should have realized a Protector would have built strong. But it raises a thought in my mind that the Protector may have survived. Or there may be more Protectors than we knew. This place is complex. I am sure now that there are control centers we have not touched. They must have built many redundancies."
"Well, let us run the reaction motor again as we leave, however we get out," said Dimity. "That will leave their possible survival, trapped in this damage, an academic matter until we summon security forces to make sure. Even a Protector can hardly cross space without a ship or a functioning motor. Vaemar, I hope we have done both our kinds a service this day."
"The hatch is opening," said Vaemar a few minutes later. "I think we should go as destructively as possible."
Dimity slid into the couch beside him. Again, one operated the gravity motor and the other the reaction-drive. On a pillar of incandescent plasma-gas the ship rose, slowly, out of the tube which led to the surface.
"I can't hold it!" Dimity cried. "We're in a gun-barrel. The ship will implode!"
"All right! Let it go. I think we have done what we can."
A dark tunnel, a growing circle of light. Space suddenly infinite about them, the disk of Wunderland hanging huge in the meteor-streaked blackness. Behind them, fire venting from the hole in the hollow moon, fire which they hoped had burnt out its core and everything in it.
"Home!"
"Home!"
A green light blinking on the control panel—the kzin color for danger. Vaemar's claws flashing on the keyboard.
"The ship identifies another engine starting," he said. "The signature is that of a kzin Rending Fang-class fighter. It is behind us."
"The Protector!"
"I suspect so. In Chorth-Captain's ship."
"Use the shielding!"
"Dimity, I am trying to discover how. I know how to pilot kzin craft, but the Protector's innovations are new to me. Throw the gravity motor into parallel with the reaction-drive. We need speed!"
"Can we fight?"
"This is a naval gig. It has stealth if I can find it, but it is not built for speed. Nor has it adequate weapons to take on a fighter. We cannot ram. We must run. Fly the ship, Dimity, while I track the stealthing commands . . . you must dodge."
They flew, firing missiles and decoys behind them. Vaemar gave a snarl of rage and stabbed with one claw point at a dial in front of Dimity in the pilot's seat.
"Another source of neutrino emissions! Another engine starting! Not a gravity engine. Nothing this boat's brain recognizes. Dimity, I think we have been over-optimistic about the number of Protectors on the Hollow Moon and the damage we did. It is still under control and I think it is either moving or preparing to fire at us. I guess there are several Protectors still alive in it. I will launch more decoys."
He stabbed at another switch. "The God be thanked that the mechanisms on this vessel have not been altered from Navy standard too much. The decoys operate. Now, Dimity, fly as you have never flown before! Use that brain of yours to fly in random variations a Protector cannot anticipate."