KIRK WATCHED THE GATE as they waited. Unlike the nexus—the junctions that joined the individual gates—the gates maintained a constant size, this one approximately five hundred kilometers in diameter.
But the display of energies was no less spectacular, and the realization that a million such displays had been operating continuously for tens of thousands of years was almost impossible to conceive of. Whatever the source of those energies, it must be literally astronomical, as if someone had harnessed the Shapley center itself.
Despite the virtual certainty that the system was beginning to break down, to spring dangerous leaks, some of which threatened the very existence of the Federation, Kirk could not help but feel a gut-wrenching regret at the thought of destroying the entire system. Not just shutting it down, which would take far more knowledge than either Kremastor's people or Federation scientists yet possessed, but destroying it.
To shut it down, the energies involved would have to be understood, and Kremastor's people, after generations of study, had not had that understanding, any more than Benjamin Franklin had had an understanding of the nature of electricity when, with more daring than sense, he had almost killed himself by pulling a bolt of lightning from the sky with a metal key on a kite string. They had learned to measure and manipulate the energies to a small extent, but primarily by trial and error. The basic nature and source of those energies were no less mysterious now than when Kremastor's ancestors had stumbled onto that first gate.
But perhaps the situation was different now, Kirk found himself rationalizing as he continued to watch the gate's almost hypnotic pyrotechnics. After all, none of Kremastor's people had realized that the gates were connected not just to different parts of their own universe but to totally different universes. With this new and critical information to work with, understanding might come more quickly than anyone could imagine.
Perhaps the differences between the energy levels of the different universes were themselves the source of the energy that drove the gates, just as the difference between the energy level of a thundercloud and the energy level of the ground below produced bolts of lightning. Perhaps, with this information, the Federation could learn to fully control the energy, not just manipulate it empirically—blindly—with no real understanding of what they were doing. Perhaps the system itself could be controlled, even temporarily shut down while a solution to the problem of the entity was sought. The thought of its total destruction and the resultant immeasurable loss ran counter to everything Kirk had ever felt.
Especially now that it was clear that not just one universe but several were involved. There was, in fact, no longer even a reason to assume that any two gates were in the same universe. Instead of a million gates spread throughout a dozen or a hundred universes, it could be that each and every gate opened into a different universe. The nexus in the Sagittarius arm might be the only opening in that entire universe.
Except for the leaks.
But wherever the gates led—could it be to different times as well as different universes?—was there no way to avoid destroying them? Now that the existence of the deadly creatures that roamed the system was known, now that the crew of the Enterprise had successfully coexisted with one of them for several days, wasn't it at least possible that, with this knowledge, the rest of the Federation could be taught to do the same?
Until real, full-scale communication with the creatures could be established?
Spock had already come close to communicating, particularly on his last attempt. And he insisted that he had detected no "hostility" during that or any other contact.
Was communication the answer? Kirk asked himself abruptly. It had proven to be the answer—the only possible answer—dozens of times before. Even in that chain of wars that had been raging for thousands of years before the Enterprise had become involved, the answer had been communication. Once the latest in the long line of combatants had begun to talk to each other, the destruction had, at least for the time being, stopped.
But in that instance, the warring factions had both been humanoid, not even all that different from each other physically or mentally.
Here, despite Spock's findings, Kirk couldn't even be positive he was dealing with a living being.
Shuddering inwardly at the memory of the paranoid fear the creature had generated during its brief attempt to control him, Kirk realized that there was really no decision to be made.
He had no choice.
For the sake of the Federation, for the sake of those other, unknown future civilizations, he dared take no chances.
If the maps Kremastor had given them were correct, the Enterprise would have just under three hours from the time it emerged from the central nexus to the time when the first window to the Sagittarius nexus opened.
They would spend those three hours gathering as much information as they could, but when the time was up, they would leave, no matter how little—or how much—they had learned. They would not try to convince Kremastor that he should postpone the completion of his millennia-spanning suicide mission for the sake of gaining more knowledge, not even for another single eight-hour cycle of the nexus.
But even as the determination firmed itself in Kirk's mind, Kremastor's voice forced itself through the static from the other ship: "Begin the approach."
Kirk braced himself as both ships surged forward. If the modifications to Kremastor's nullifier were as successful as the modifications to the Enterprise's artificial gravity system had been—full impulse power now produced only the slightest hint of any imbalance—there would, at more than half of light speed, be only a flicker as they entered the gate and emerged from the central nexus milliseconds later.
If the modifications had not been successful, and the Trap had not been nullified—Tensely, he waited as Spock counted down the seconds.
And suddenly, between the syllables of "zero," the gate and the millions of parsecs of emptiness that surrounded it were replaced by a field of stars that could have been those of the Federation.
Relief flooded through Kirk. They had made it!
An instant later, the relief was replaced by a sudden chill.
The entity, whose presence had been growing stronger virtually up to the moment of entry into the gate, was gone!
"Spock, can you detect the entity's presence?" he asked sharply.
"No, Captain. And Kremastor's ship," Spock added, indicating the viewscreen, "appears to be gone as well."
Abruptly, Kirk swung back to face the screen. Spock was right. During the approach to the gate, Kremastor's tiny ship had been only a few hundred meters distant, clearly visible, but now there was nothing, not even the nexus from which they had just emerged.
"The sensors, Spock," he snapped, but Spock had already turned and was absorbing the multiplicity of readouts.
"Nothing registering, Captain," he said after a moment. "But the sensors now have a range of less than ten kilometers, and that range is already decreasing rapidly."
"Full stop, Mr. Sulu. I want us perfectly still before the local laws take over and ruin our artificial gravity again."
"Full stop, sir."
"Lieutenant Uhura, any signals?"
"Nothing but static, sir."
"Mr. Spock, how soon before the bubble—"
Abruptly, everything wavered, just as it had in that other universe.
And colors returned to normal.
"Does this mean," Ansfield said, looking at the restored science blue of McCoy's uniform, "that we're at least back in our own universe?"
"Perhaps, Commander," Spock said. "That could account for the speed with which the bubble shrank. In that other universe, our minds were opposing the changes, while here, if your hypothesis proves true, our minds would aid the—"
"Mr. Spock!" Lieutenant Crider's voice broke in from the physics lab, where he had been stationed, poised to perform as quickly as possible the same measurements Spock had done in the previous universe. "Initial results indicate c and the gravitational constant are virtually identical to—to 'normal' values."
"That's good enough for me," Kirk said abruptly. "Mr. Scott, get started putting things back the way they were, sensors top priority."
"Aye, Captain," Scott's voice came from engineering. "It'll take a wee bit longer ta do the transporters and the artificial gravity anyway."
Spock fed the necessary programming changes into the computer. In less than two minutes, Scott reported the sensor circuits were all returned to their original configurations. Moments later, as the sensors were reenergized, the nexus reappeared on the screen. It was the same kaleidoscopic maelstrom they had seen in the Sagittarius arm, flickering in and out of existence, expanding and contracting wildly.
"Full sensor capability, Captain," Spock announced, "but there is still no indication of Kremastor's ship or of any significant amount of matter closer than the nearest stellar system approximately half a light-year distant."
"Could he be out of range?"
"Only if he has gone into warp drive, Captain—which would be impossible for him in this universe without massive modifications to his warp engines."
"Then he either didn't enter the gate when we did or he somehow stayed inside."
"Or the Trap's still working after all," Ansfield added. "If the entity isn't with us anymore, maybe it attached itself entirely to Kremastor, and that's why we got through and he didn't."
"Or the two of them are in cahoots!" McCoy growled. "Maybe that whole show they put on for us back there was just a fake to get us here. Wherever the blazes 'here' is!"
Ansfield shook her head. "You're too suspicious, McCoy. But there's only one way to find out: go back in and look for him. Besides," she added, turning to face Kirk, "we need him. Without Kremastor and his ship, there's not a whole hell of a lot we can do here."
"Unfortunately, Commander, you're right," Kirk agreed. "Mr. Spock, if we do go back into the nexus, can the computer, now that it has a complete set of maps, be trusted to get us back out of there, the way it got us out of the Sagittarius nexus?"
"The maps can be trusted only to the extent that anything connected with the nexus system and the entity can be trusted, Captain."
McCoy snorted. "If I didn't know you better, Spock, I'd say that sounded an awful lot like another 'Your guess is as good as mine.'"
"In this case, Doctor, it is. As I have often stated, logic cannot make reliable predictions without sufficient factual data on which to base those predictions. If you accept Kremastor's story as fact—"
"We can argue philosophy later, gentlemen," Kirk broke in. "Whether we can trust what Kremastor told us or not, we only have two choices. We can go into the nexus and search for Kremastor and the device he said is capable of permanently shutting down the system. Or we can learn as much as we can here and then return to the Sagittarius nexus and hope that what we've learned will be enough to keep the Federation from self-destructing. But unless one of the things we learn is a way of plugging the leaks in the system—"
"Captain!" Uhura interrupted. "Standard electromagnetic signal coming in on several frequencies!"
"Source?"
"One-seventeen, mark thirty-two."
"Spock, sensor scan."
An eyebrow arched minutely as he bent over the displays. "Nothing within range, Captain, but that heading coincides with the center of the nexus."
"And the signals are similar to those we received inside the nexus, sir," Uhura said, "the ones that gave us the first of the maps."
"Another map?" Kirk frowned. "A duplicate of what Kremastor has already given us?"
"I do not believe so, Captain," Spock said. "Although the computer cannot yet extract any intelligible information from the signals, it is able to compare the raw data it is receiving with the raw data it received before, and there are no matches. As yet, this is totally new information."
"Which is what we're here for," Kirk said abruptly. "It looks as if our search for Kremastor has been delayed."
Like the signals that had given them the maps, the new signals were designed for direct communication between relatively primitive computers. As a result, the data transfer rate was slow, almost as slow as the rate by which the data making up the original maps had been transferred. The window to the Sagittarius nexus was little more than an hour away when the flow of data finally stopped and the computer began its analysis.
Spock leaned closer, watching the computer readouts as the analysis progressed. After a minute, one eyebrow arched.
"Not just another map, Mr. Spock?" Kirk asked.
"No, Captain. The signals this time appear to have provided two things. First, an extensive language lesson so that what followed could be comprehended. And second, a warning."
"Warning?" Kirk said sharply. "Against what?"
"The use of the nexus, Captain. I can only assume that the warning was designed for those ships approaching the nexus from space, not those emerging from within the nexus. The warning directs us to keep a minimum distance of more than a billion kilometers."
"Nice of them. Could that be the range of the entity?"
"Such a range would not contradict our own experiences, Captain."
"And what else does this warning say? Even at a data transfer rate as slow as theirs, there had to be more than that."
"There is, Captain, a great deal more. Much is in the form of mathematical equations, presumably describing the nexus system itself, but there is what appears to be a lengthy verbal message as well."
Kirk glanced at the kaleidoscopic energies of the nexus. "Mr. Sulu," he said, "lay in a course to take the Enterprise through that window to the Sagittarius arm and back to Starfleet Headquarters. Set it to execute automatically if we ourselves are unable to do so. I want to be very sure that whatever is in our computer gets back to the Federation even if we don't."
"Aye-aye, sir."
"Now, Mr. Spock, let's hear that message."
"As you wish, Captain." Spock's fingers darted across the science station controls, and a moment later a thin and reedy voice emerged from the computer.
"I am the last of the Risori," it began.
And as the words flowed, it slowly became clear what had happened, nearly a thousand centuries ago, to the people who called themselves the Risori.
More importantly, it became clear that this was the central nexus, the one from which the entire nexus system had sprung.
The warning, as most on the bridge already suspected, had been against the entity, the infection.
And, not surprisingly, the Risori were indeed the ones responsible for the nexus system.
What was surprising was that they were almost totally ignorant of its workings. They understood even less about the forces involved than had Kremastor's people. Their technological level, in fact, appeared to be well below that of the Federation. The method of data transmission employed in the warning was not, as Kirk and the others had assumed, a concession to the possibly less advanced races for whom the Risori had left the warning. Instead, it was, for them, state of the art.
In addition, the Risori hadn't even developed a rudimentary warp drive.
And the entity, the infection, was an even bigger mystery to the Risori than it was, now, to the crew of the Enterprise. The Risori who left the warning, the last of his race still alive at the time, knew only that it had suddenly appeared somewhere in the nexus system, that it had infected one or more of the exploratory ships, and that their own world and the half-dozen colony worlds that were all they had established during generations of nexus exploration were virtually wiped out by wars within a year.
The Risori, although "responsible" for the nexus system, had not "built" it, nor had they simply found it, as Kremastor's ancestors had done. What they had found was the equivalent of a single gate, apparently fixed in space as their solar system moved slowly past it. For several years, it was within easy reach of their impulse-power technology, and before long, a ship had entered the gate. And found itself—elsewhere.
For years, the Risori probed the gate with every instrument their scientists could devise. And eventually they discovered within the gate a new form of energy, the mathematical descriptions of which suggested to both Spock and Ansfield that it was closely related to the energies that were manipulated when a ship went into warp drive.
And they learned to harness that energy, first for their own ships, then for their world. Just as nineteenth- and early-twentieth-century humans had been able to use and mathematically describe electricity without ever understanding its true nature, the Risori used and mathematically described the energy they obtained from within the gates.
But then, purely by accident, they turned that energy back on the gate itself.
The gate had instantly expanded, and when a ship entered the enlarged gate, it found itself at a different "elsewhere."
By the same kind of trial-and-error methods that Kremastor's people had used millennia later, the Risori "developed" the nexus system for more than a generation then, feeding the energy back into it in a hundred different ways, opening a hundred different gates.
And with each new gate, the available energy increased.
And changed.
Then, without warning, the gate became a nexus.
A vortex, spinning madly through whatever dimensions it existed in, opening thousands of gates, one after the other.
Like a tornado born out of the complex, conflicting energies in a planetary atmosphere, a nexus was born out of the energies within the gates, the energies that had been blindly twisted and altered by the Risori.
And the nexus sustained itself on those same energies.
And spawned new vortices, new nexus. For Kirk, his midwestern childhood suddenly fresh in his memory, the description stirred vivid images of tornado after tornado growing out of the energies of a single violent thunderstorm. He even wondered if the tiny "pockets of reality" they had found in the very centers of the nexus were somehow analogous to the eye of a hurricane, a point that remained perfectly calm while destruction raged all about it.
And he marveled that the Risori, knowing they had virtually no control and little real understanding of this awesome process, had ever brought themselves to enter it, to even attempt to chart it.
But enter it they had, for a half-dozen generations.
Even so, there were so many destinations available that only a minute percentage were ever actively explored. The "maps," broadcast throughout the nexus system by transmitters safely hidden in the "reality bubbles" within the nexus themselves, were the equivalent of an astronomer's map of the sky, in which the only information for a vast majority of the stars is their locations, simply telling another astronomer where to point his telescope to look at specific stars. The nexus maps the Risori generated gave similar information, but the "location" corresponded to a specific time during the cycle of a nexus.
The only other information consisted of codes indicating which gates had been passed through and the conditions found on the other side. In those rare instances, such as the Sagittarius nexus, where the destinations were within galaxies or star clusters, maps of the stars surrounding those gates were made. In those even rarer instances, six in all, in which a habitable planet was found within impulse-drive range of a destination, the Risori established outposts, then colonies.
And because they put virtually all of their resources into exploring the nexus system, they never developed warp drive, which, ironically, could have given them ten or a hundred times the six habitable planets that the nexus system ever gave them.
And then the infection—the entity—came.
No one knew what gate or gates it had come through.
No one knew what it was or what it wanted, even if it was a living thing.
No one knew how to stop it. They only knew, too late, that it was destroying
them.
And then the Risori were gone, leaving behind only the maps and the warning, which, powered by the same energies that had created and sustained the nexus, would continue as long as the nexus themselves remained in existence.
The Sagittarius arm window was less than five minutes away when Kirk gestured for the Risori voice to be silenced.
"Is the system controllable, Mr. Spock?" Kirk asked sharply.
"Based on the limited information so far obtained, Captain, I would say yes, but not for many years. Even the simplified mathematical descriptions included in this message indicate that a warping of space itself plays a major role, but the equations require at least six dimensions to be valid. As far back as the twentieth century, however, there have been theories requiring the universe to have as many as eleven dimensions, so this by itself is not—"
"We have only four minutes to make a decision, Mr. Spock. Your best guess as to how long it would take to turn mathematical theories into something that could shut down an existing nexus without destroying the entire system?"
"A basic understanding could conceivably be achieved within a decade, Captain, but to convert that understanding into physical equipment capable of manipulating those forces—"
"Commander Ansfield?" Kirk interrupted. "Do you agree?"
"I certainly can't see it being done any faster. That was not freshman calculus being tossed around there."
"Then we have no choice. Returning to the Federation with no more than we have now would be pointless. Our only chance is to find Kremastor and hope that he's able to complete his mission."
"And if we can't find him?" Ansfield asked.
Kirk turned abruptly to the helmsman. "Mr. Sulu, you have three minutes to get a shuttlecraft ready to enter the nexus. Spock, Uhura, transfer as much data as possible concerning the entities and the nexus system to the shuttlecraft's onboard computer."
Acknowledging, they began.
Sulu brought the Enterprise about and, on full impulse power, took it to within a dozen kilometers of the nexus, then hastily checked that the remote controls were still engaged and that the shuttlecraft answered the helm.
Spock, mentally calculating shuttlecraft computer capacity as he worked, selected blocks of data and routed them to the communications section, where Uhura fed them directly to the shuttlecraft computer. At the same time, she initiated a series of commands that would cause the shuttlecraft, once through the nexus and in the Sagittarius arm, to continuously broadcast the information on as many subspace channels as the shuttlecraft communications system could handle, including Starfleet Headquarters' top-priority emergency channel.
"Ready to launch, Captain," Sulu said as the hangar deck doors clamshelled open.
"Get it under way, Mr. Sulu. Thirty seconds to the Sagittarius window."
"Aye-aye, sir."
But even as Sulu reached for the controls, his fingers barely an inch from the buttons that would send the shuttlecraft sweeping out through the hangar deck doors and into the nexus, he froze under a sudden avalanche of paralyzing terror.
The entity, wherever it had been the last three hours, had returned, with a vengeance.