According to even the most conservative estimates, the Milky Way galaxy contains more than one hundred billion stars, and there are at least that many other galaxies beyond our own, beyond the reach even of warp drive. This means that for every human alive on earth at the end of the twentieth century there are twenty or more stars in our home galaxy alone, and countless billions more are spread throughout the clusters and superclusters of other galaxies, stretching to the very edge of the universe -- if, indeed, an edge exists. It is therefore little wonder that, even with Federation, Romulan, and Klingon ships spreading throughout space at unprecedented rates, more than ninety-nine percent of even that one galaxy is unknown and untouched by human -- or Romulan or Klingon -- sensor probe. Even within the territory covered by the Federation Exploration Treaty, the unknown far outweighs the known as scout ships leapfrog over thousands of star systems in their rush to explore, to reach new horizons.

Under such circumstances, then, it is easy to go where no man has gone before. It is, in fact, often unavoidable. To survive such explorations and to return safely -- that is another matter altogether.

"I fail to see the humor in the situation, Dr. McCoy."

As always, Spock's remark held neither anger nor resentment. It was simply a statement of fact, edged with the faint touch of bemused bafflement that was always present when the Vulcan science officer was dealing with less-than-logical humans.

"I know, Spock, I know," McCoy said, stepping back to give Spock ample room as the Vulcan's long, powerful fingers continued to methodically work the science station controls. "But you don't mind if we humans indulge in a good laugh now and then, do you?"

"Of course I do not mind," Spock said, most of his attention still devoted to analyzing the station's readouts for some sign of the probe that had been launched more than five minutes before. It was rapidly becoming apparent, however, that the probe was not going to reappear, either five parsecs away or five hundred, all of which struck McCoy as a fitting and somewhat amusing climax to the totally erratic behavior of the previous forty-odd probes.

"In fact, Doctor," Spock went on, still not taking his eyes from his instruments, "as you yourself have pointed out, such outbursts often seem to have a therapeutic effect on your species. It would hardly be logical for me to wish to deny you something that could improve your physical and mental well-being and hence your efficiency in performing your duties."

McCoy chuckled, still watching the display screens over Spock's shoulder. "Maybe it's just as well you don't ever laugh, Spock. You're already too blasted efficient. I'd hate to see what would happen if you ever developed a sense of humor. Jim and I and half the crew would only be excess baggage."

"Another example of human humor, I assume, Doctor. I find it difficult to believe that even you would look favorably on inefficiency. But if I may be allowed to--"

A shudder rippled through the Enterprise, momentarily shifting the deck beneath their feet. Spock, rock steady despite the movement, called up a dozen new displays on the screens.

"Another shift in field strength, Captain," he said, "an increase of twenty-seven-point-one-six percent. I would suggest drawing back approximately ten A.U. as a precautionary measure."

"Take us back ten A.U., Mr. Sulu, warp factor three," Kirk said without hesitation. He had long since learned not to question his first officer's suggestions. "Hold steady at that position."

"Done, sir," the helmsman said, his fingers already entering the commands into his console.

McCoy, silent now as he gripped the padded handrail to steady himself, turned toward Kirk. Seated in the command chair, the captain was intent on the forward viewscreen, where the flowing ribbon of the Sagittarius arm of the galaxy overlay the distant turbulence of the Shapley Center. As they watched, the star field rippled briefly, much as the bridge itself had seemed to ripple a moment before.

"Another change in the field strength, Mr. Spock, or just the result of our motion in the field?"

"Our motion, Captain, with respect to the irregularities near the anomaly itself. The field remains steady at its new level."

"And the last probe, the one whose disappearance Dr. McCoy found so amusing -- still no sign of it?"

"None, Captain."

"A malfunction in the probe itself, perhaps?"

"Unlikely, Captain. As you know, the probes are little more than powerful subspace beacons attached to impulse engines. Considering the simplicity of their design and construction, the likelihood of any vital component failing has been statistically established to be less than one in one-point-three million."

"But it is possible," Kirk persisted.

"Possible, yes, Captain, in the same sense that anything, no matter how unlikely, is statistically possible."

"Point taken. What other explanations can you suggest?"

"The most likely is that the probe is beyond the range at which it can be detected."

Kirk swung his chair to look directly at the science officer. "Out of range, Mr. Spock? I was given to understand that their signals could be picked up at a range of more than five thousand parsecs."

"Five thousand four hundred eighty, to be precise, Captain, though that is, of course, only the minimum guaranteed range."

"You're saying this -- this 'gravitational anomaly' could have transported the probe more than five thousand parsecs?"

"Obviously, Captain."

"But none of the other probes has reappeared at any distance greater than five hundred parsecs."

"Affirmative, Captain."

"That's it, Spock? No elaboration?"

"If you wish, Captain. As you and Dr. McCoy are certainly aware, we have been unable to establish any logical pattern based on the behavior of the probes sent through the so-called anomalies. Some have not been affected at all, as if for them the anomalies do not exist. Others have vanished and emerged into normal space little more than one parsec distant, while still others have reappeared nearly five hundred parsecs away in a totally different direction. There is therefore no logical reason to assume that the range is limited in any way. The distance a probe is transported is apparently not related in any way to its entry velocity. It is more likely a result of the geometry of space itself and the manner in which it is distorted by these socalled anomalies, and that distortion appears to vary randomly from moment to moment, even to cease entirely on occasion."

"From your repeated use of the phrase 'so-called anomalies,' can I assume that your observations have suggested a more useful or more accurate term?"

"Not at all, Captain. It is only that I am beginning to doubt that these objects are indeed something as simple as anomalies resulting from surrounding areas of gravitational turbulence."

"What, then?"

"I do not know, Captain."

"But you must have some thoughts on the subject, Spock."

"Of course, Captain."

"And those thoughts are...?" Kirk prompted.

"I can only say, Captain, that there is a distinct but unquantifiable possibility that they are not natural phenomena at all."

In the silence that followed, all eyes on the bridge turned to Spock. Then a short burst of laughter came from McCoy.

"An unquantifiable possibility?" McCoy said, shaking his head in mock surprise. "That isn't your Vulcan way of saying you have a hunch, is it, Spock?"

"It is hardly a hunch, as you chose to call it, Doctor. It is merely that the results of our observations so far appear totally random and therefore illogical. Past experience has led me to conclude that phenomena which appear to be illogical are less often the result of natural laws than they are the result of manipulation of those laws by intelligent but less-than-logical beings."

Captain James T. Kirk suppressed a smile as he nodded and shifted to a more comfortable position in the command chair. The thought that the anomalies were not natural phenomena had, of course, occurred to him, but, as Spock would say, he had not assigned it a high probability factor. For one thing, when the Enterprise had first run into one of the anomalies -- run into it quite literally -- the ship had been instantaneously transported more than three hundred parsecs and damaged by the effects of the surrounding turbulence. Under those conditions, everyone's priorities had centered on survival, both their own and the Enterprise's, leaving little time for scientific analysis or philosophizing.

But now it was a different matter. Equipped with newly designed sensors that allowed them to precisely locate -- and avoid -- the strangely complex turbulence, and supplied with more than two hundred probes, they had come to study what was apparently a cluster of such anomalies discovered by a scout ship not long after the Enterprise's return from the Mercanian system, where the first anomaly had deposited them so unexpectedly. Or, more accurately, they had come to study a cluster of gravitationally turbulent areas in order to determine if any or all of those areas contained at their centers the same type of anomaly that had swallowed the Enterprise and then spit it out three hundred parsecs away. By sending the probes through such anomalies, they had hoped to determine just where the anomalies led.

Anomalies had indeed been found in the centers of seven of the areas of turbulence so far, and forty-eight probes had been dispatched. Six had passed through the anomalies without effect, emerging on the far side with no indication of damage or change of any kind. Forty-one had reappeared at distances ranging from one to five hundred parsecs, in directions that bore no discernible correlation to anything. Two probes sent through the same anomaly within milliseconds of each other reappeared more than six hundred parsecs apart, one in the direction of the Shapley Center, the other in the general direction of Klingon territory.

In short, as Spock had said, the operation of the socalled anomalies appeared totally illogical and had thus far defied analysis. And now one of the probes had simply vanished, either transported beyond the five-thousand-parsec range of its transmitter or destroyed or...

"Could the disappearance be related to the shift in the field strength, Mr. Spock? The two occurrences were fairly close together."

"It is possible, of course, Captain. Without further data, however, there is no way of confirming or denying the hypothesis."

"Another probe, then, Mr. Spock?"

The hiss of the doors to the turbolift forestalled Spock's reply. A stocky man in his fifties, his tightly curling hair beginning to gray, strode onto the bridge. His angry glower, as much as his green civilian tunic, distinguished him from the Enterprise personnel.

"What sort of nonsense have you been up to now, Kirk?" the man snapped, making the omission of the captain's rank sound more like an insult than an oversight.

"Welcome to the bridge, Dr. Crandall," Kirk said dryly. "What seems to be the problem?"

"The problem, Kirk, is that I was awakened only moments ago by something which, were I on a planetary surface, I would describe as an earthquake. I would like to know the cause, and I would like to know why it was not avoided, whatever it was."

Kirk turned away from Crandall toward the science officer's station. "You have the floor, Mr. Spock."

A minuscule arching of one upward-slanting eyebrow was the only change of expression as Spock turned to face Crandall. "The cause, Dr. Crandall, was an unpredicted and abrupt change in both the overall strength and the pattern of the gravitational field surrounding the so-called anomaly we are currently observing. The reason it was not avoided is that it was unpredicted. To the best of our knowledge at this time, such changes cannot be predicted."

Crandall, still not fully accustomed to the Vulcan's calm and rational ways, seemed to lose some of his steam.

"I see," he said. "But the ship -- the ship was not damaged?"

"Not a bit," Kirk assured him. "As you know, the new sensors allow us to--"

"I know, I know," Crandall snapped. Then he glanced around the bridge, his eyes settling on the forward viwscreen. "There's an anomaly out there? A new one?"

"That's right," Kirk said. "The seventh."

"Why wasn't I called? I am, after all, an official observer, which would seem to me to mean that I should be present during all observations."

"If you will recall, Dr. Crandall," Kirk said quietly, "midway through our observations of the previous anomaly, you told us you didn't want to be bothered unless something unusual happened. 'Something downright spectacular,' I believe were your exact words."

"Something that can rattle the walls of a Constitution-class starship qualifies as spectacular in my book, Kirk. In any event, now that I am here, would anyone care to bring me up to date?"

"Of course, Doctor," Kirk said, turning away again. "Mr. Spock?"

"Very well, Captain," Spock said and then began a probe-by-probe account, complete with all particulars, of all observations since Crandall's hasty departure on the previous day's watch.

Kirk settled back to listen and to wonder once again what Starfleet Command had had in mind when they had allowed Dr. Jason Crandall to be attached to the Enterprise as an "official observer." True, Crandall had been in charge of the Starfleet-supported civilian labs that had developed the sensors that had been installed on the Enterprise, but Crandall himself, despite a doctorate in physics, was far more of a politician than a scientist. Otherwise he would never have been in charge of that or any other lab, Kirk was sure. And it had become abundantly clear after only a few days on the Enterprise that Crandall saw the labs -- and this mission involving the sensors developed there -- primarily as stepping stones to greater things, perhaps even to a seat on the Federation Science Council.

Kirk shuddered mentally at the thought. He did not naively believe that Council seats were attained purely on merit, but neither could he believe that merit and ability had no bearing at all on the matter. All current members were, at the very least, competent, some even brilliant, and the thought of Crandall bluffing or conning his way into their company was growing more disturbing each time Kirk had contact with the man.

"All right, Spock, all right!" Crandall's harsh voice cut into Kirk's thoughts. "I don't need the trajectory and serial number of every probe! All I wanted was a brief summary. Have you or have you not discovered any pattern?"

"Negative, Doctor."

"And do you foresee any such discovery?"

The Vulcan's eyebrows arched again, not quite as minutely as before, and his eyes flickered toward Kirk for an instant. It was, Kirk realized, as close to exasperation as he had seen Spock express in some time.

"It is impossible to foresee a discovery in the sense you seem to mean, Doctor," Spock said. "If, on the other hand, you wish to know if I expect such a discovery to be made, then I can only say that I have every confidence that, in time, it will be made."

"But not here and now? Not in the next few hours or even in the next few days or weeks?"

"Again, Doctor, that is impossible to say."

"Good Lord, man! I'm not asking for an oath signed in blood! All I'm asking is if you think you'll be able to get to the bottom of this before you run out of probes!"

"With no more data than I have at present, it would be illogical to form an opinion one way or the other, Doctor."

McCoy, who had moved away from the science station during the exchange, stifled a laugh and, when Kirk glanced at him, could only shake his head. He was obviously enjoying Crandall's frustration, all the more because he himself had so often collided with Spock's implacable wall of logic.

Then, abruptly, another shudder rippled through the Enterprise, not as powerful as the first but enough to send both of Crandall's hands clutching at the padded railing.

"What--" he began, but before he could get a second word out, Spock was checking his instruments and reporting.

"The field strength has decreased to zero, Captain."

"It's gone, Spock? The area of turbulence has disappeared?"

"Precisely, Captain."

"And the so-called anomaly at its center?"

"Unknown, Captain. I would suggest dispatching another probe."

Kirk considered a moment before turning to face the viewscreen again. "Take us back to within probe range, Mr. Sulu. Warp factor two."

"Warp factor two, sir."

"Any indication of renewed turbulence, Mr. Spock?" Kirk asked, his own eyes fastened to the forward viewscreen.

"None, Captain."

Finally they were once more within one hundred thousand kilometers of the anomaly, and Spock's fingers were moving unerringly across the controls of the auxiliary panel that was linked to the probes. As before, the probe would be beamed to within five thousand kilometers of the anomaly using the cargo transporter. From that point, it would proceed under its own impulse power into the anomaly.

Even so, several minutes went by before Spock looked up from the controls.

"The so-called anomaly has vanished, too, Captain."

"And what does that mean, Spock?" Crandall cut in. During the seemingly interminable wait, he had alternately stood and paced, fidgeting and frowning impatiently all the while.

"It means precisely what I said, Doctor," Spock said. "The anomaly associated with this particular area of gravitational turbulence appears to have vanished at the same time as the turbulence itself."

"What about the others? There are a dozen others nearby, aren't there?"

"There were fifteen in all, Doctor. There is no way of knowing their status without traveling to the vicinity of each and checking."

"Well, what are you waiting for?" Crandall demanded.

"Captain?"

"Your opinion, Mr. Spock?" Kirk asked.

"It would seem logical to check at least one of those we have already visited, Captain, to see if the disappearance is limited to this one anomaly."

Crandall heaved a sigh of annoyed relief. "And if it's gone, too, then I assume we will be heading back to the Federation. It seems to me, considering the total lack of useful results obtained so far, we have wasted quite enough time on this project. Kirk?"

"As you have said, Dr. Crandall, you are an observer," Kirk said, his tone nearly as neutral and precise as Spock's. Then, turning back to the forward viewscreen: "Lay in a course that will take us to all six previously visited anomalies, Mr. Sulu. And Mr. Spock, keep an eye on those new instruments. We don't want another unscheduled trip."

"Of course, Captain," Spock said, and a moment later Sulu acknowledged that the requested course had been laid in.

"Cautiously, then, Mr. Sulu. Warp factor two."

"Warp factor two, Captain."

On the forward viewscreen, the distant Shapley Center slid to one side and vanished as the Enterprise turned and aligned itself for its new destination. In a few seconds, only the scattered stars of the outer edge of the Sagittarius arm of the galaxy could be seen, and beyond them the faint band of light that was the Orion arm, one tiny patch of which held all the stars within the Federation.

"How long will this -- this exercise in futility take, Kirk?" Crandall snapped, a new level of hostility evident in his voice.

"The original observations were scheduled to take three standard weeks."

"But if there's nothing left to observe--"

"Then perhaps it will take somewhat less time."

"Perhaps? Good Lord, man, do you mean to say--"

"I mean only to say," Kirk cut in, "that this disappearance merely deepens the mystery surrounding the nature of these anomalies, and that I can see no reason to cut short our mission until we have learned all that we possibly can."

"Commendable scientific curiosity, I am sure, Kirk, but rather pointless, it seems to me. In any event, I postponed important business to become a part of this mission, and I strenuously object to having it prolonged unreasonably. That is to say, beyond a point at which useful knowledge can be obtained. A point which, I might add, appears to have been reached some time ago."

"You are, of course, free to contact Starfleet Command at any time, Doctor. Lieutenant Uhura will be glad to open a channel whenever you wish."

Crandall's square features hardened as his jaw muscles tensed, and Kirk imagined he could hear the grinding of teeth. Then Crandall slumped slightly, confirming Kirk's suspicions that friendship with the people at Starfleet Command was not the reason Crandall was aboard. He or his political friends had pulled strings somewhere, and Starfleet Command had obliged, as they often did in small matters that did not interfere with Starfleet activities. The string pulling had gotten him aboard the Enterprise, in a position to take advantage of any significant discoveries that resulted from the use of his lab's sensors, but that was all it had gotten him. And even that might be lost if he pushed his luck.

"I may do that, Kirk," Crandall said. "If this nonsense continues much longer, I may do just that." But both men knew it was an empty threat.

Kirk remained silent, and finally Crandall turned to leave the bridge. But as he took a step forward toward the turbolift, another shudder gripped the Enterprise. Compared to the two previous incidents, it was almost unnoticeable, not even enough to cause Crandall to miss a step.

A moment later, however, Chekov's voice, high-pitched with excitement, sliced through the air. "The screen, sir! Look!"

Kirk spun the command chair instantly to face the viewscreen.

He blinked, and fingers of ice suddenly gripped his spine.

Instead of the sparse stars of the edge of the Sagittarius arm, there were stars by the thousands, by the tens of thousands, a star field immeasurably brighter and more dense than anyone on the bridge had ever seen.