“LET ME GUESS,” said Dr. McCoy, in the hissing silence of the carbide-lit tent. “You were trying to destroy this central hub and stop the Gorn from invading the Federation when we hauled you out of your timeline and into ours.”
“Yes.” The glint of triumph faded from Sulu’s lined face, and left him looking older and more tired than before. He glanced down at what was left of his right arm. “Trying, but not succeeding. The Gorn hub is probably still there and still working.”
“What happened?” Uhura asked.
“We were ferrying troops to a newly invaded Vulcan colony when we ran across a Romulan battleship and attacked it.” The former helmsman said those words so offhandedly that Uhura felt almost jolted. She had to keep telling herself that for this Sulu, all-out war had become a way of life. “It ran for refuge to a minor planet near the galactic fringe. When we chased after it, we got attacked by so many Gorn fighters that we knew the planet wasn’t one of their normal colony worlds. We pretended to veer off, then circled back and saw the installation they were guarding. It looked like it could be the portal hub, so we hit it with all the anti-invasion troops we were ferrying to Xlamat, in a surprise attack.” Sulu’s lips tightened to a slash of remembered pain. “They were slaughtered down to a man.”
Uhura let a moment of merciful silence pass before she spoke again. “What did you do after that?”
Sulu sighed. “We tried taking the Hotspur low into the atmosphere and firing every weapon we had—and by that point in the war, as you can imagine, we had an awful lot of firepower. It never even shook the towers above the fortress, much less the main underground portal. After that, there was only one thing left to do. We sacrificed the Hotspur to catch a Gorn shuttle and crash-landed them both, to make them think we all were dead.” Sulu glanced up at her with another of those strange, bittersweet smiles, as if the years of war had taught him to find a dark thread of humor even in disaster. “Actually, most of us were dead by then. There was only a skeleton bridge crew left—you, me, Chekov. While we repaired the Gorn shuttle, we took turns watching Tesseract Fortress and listening to its communicator chatter. We noticed after a while that there weren’t just Gorns showing up around that place—all the races they’d allied with or enslaved were there, too, massing and organizing for some major deployment. Maybe an invasion of Vulcan, we thought, or even of Earth. We waited as long as we could, but we didn’t want to let them start sending that army through the portals if we could help it.
“So we salvaged our last pulse bomb from the wreck of the Hotspur and infiltrated Tesseract Fortress. We suspected the reason our previous attacks had failed was because the portal was generating a subspace force field so powerful that it actually protected itself from attack. Once we got inside the fortress walls, we were going to take our pulse bomb into the portal and detonate it from inside while Chekov—made a distraction.”
Sulu’s steady voice didn’t falter as he recounted his own suicidal part in that final plan, Uhura noticed, but it did when he tried to gloss over the grim reality of what his subordinate had done. She reminded herself again about all the hellish years of war this man had endured, and said nothing. Dr. McCoy wasn’t quite so tactful.
“You let that boy deliberately sacrifice himself?”
“Not such a boy in my time as in yours, Doctor. And by 2296, every officer in Starfleet would have sacrificed themselves if it could save another million civilian lives. I just wish it could have been that simple.”
“You never made it into the portal with the pulse bomb?”
“No,” Sulu said regretfully. “God knows the Gorn transfer enough weapons through that hub during their invasions, but they must have detectors to pick up activated ones. They slammed their security fields down on us before we even got close to the gate, then raked us with explosive projectile weapons. I saw Uhura get hit—felt the bomb get shot out of my hand and saw it start to ignite—and then I was here.”
Sulu stopped speaking, and this time both McCoy and Uhura let the silence stretch out undisturbed until the older pilot himself broke it.
“Now do you understand why I have to go back?” he asked, pinning Uhura with a sharp, direct look that reminded her of Captain Kirk. “If my future really is your future, then the fate of my Federation and yours depends on you getting me back through this damned time transporter of yours.”
Sulu reached through a glistening film of insects to activate the Drake’s communicator, then paused with his finger just a centimeter away. Was this a trap? Could the aliens who chased him away from the military fortress have somehow learned his name, telepathically or through some exotic technology that he couldn’t even begin to comprehend?
“Sulu,” the communicator said again, impatiently. “I know you’re the only one who could have flown that shuttle, much less sent out that old Starfleet emergency signal. If you’re alive out there, say something!”
Sulu eyed the communicator in surprise. The threadlike flash of its frequency monitor told him this signal was coming in on the same restricted and high-security Starfleet channel he’d used to broadcast his coded distress call, but that wasn’t what made him take a deep breath and complete his motion toward the activation switch. Maybe he was wrong, but he couldn’t imagine any aliens, telepathic or otherwise, who would bother to speak English with a Russian accent.
“Sulu here,” he said into the communicator. “Who is this?”
“Bok spasibo!” said the thankful voice on the other end of the channel. It didn’t sound much like a name, but since Sulu didn’t know what else it could be, he decided not to make an issue of it for now. “Where are you now, Captain?”
Captain?
“I’m still in the shuttle,” Sulu said, cautiously. For all that the man he was talking to seemed to know him, there was still something very odd about this conversation. “I—uh—landed it in the rain forest. Where are you?”
“Flying low over the Serippat Hills, with the cloaking device engaged and no Gorn in sight,” the other voice said. “Keep talking and I’ll triangulate on your signal. Is… is Uhura still with you?”
Sulu paused once again with his finger centimeters from the communicator controls, this time ready to break contact. What stopped him wasn’t the familiar name of his Enterprise crewmate, but the unmistakable tension in the other man’s voice when he asked about her. That couldn’t be part of some alien plot to lure him out of hiding… even if the aliens could read his mind and know that Uhura had been down on Tlaoli with him just before he disappeared, there was no particular reason for them to pretend to be fearful about her. To the best of Sulu’s knowledge, she was still safe and sound.
“No, she’s not here,” he said. “She’s back at the base camp on Tlaoli.”
There was a long moment of silence. “What?”
The mixture of bewilderment and suspicion in that reply sounded so exactly like what Sulu was feeling himself that he was almost tempted to laugh. Clearly, whoever he was talking to found this conversation about as confusing as he did… and suddenly, Sulu’s overtired mind made a connection between this gruff, Russian-accented voice and the self-conscious young ensign he’d met just before he’d taken off to look for Captain Kirk on Tlaoli.
“Is this Chekov?” he demanded.
“Of course it’s Chekov,” was the sharp and far from self-conscious reply. “What kind of a stupid question is that? Sulu, are you wounded? Did they spray you with any of their drugs?”
“No,” said Sulu. “But something’s not right here.”
The communicator crackled, but it took Sulu a moment to recognize it as the sound of mirthless laughter. “Nothing’s been right for a long time now. Stay where you are. I have your location fixed now, and there’s still no sign of Gorn. I’ll set down in the nearest clearing and come get you.”
Sulu opened his mouth to ask Chekov who the Gorn were, how the young ensign had come to this alien planet, and where he had obtained the craft he was flying. But the thread of light marking the open high-security channel between them died abruptly back to its baseline and left him sitting in the rain and darkness, wondering what to do next.
The most prudent reaction would probably be to evacuate the shuttle, but that would put Sulu out in the darkness of an alien forest with very little equipment and even less idea of what he was supposed to do next. He reminded himself that his goal right now was simply to get back to the Federation, which made the presence of a fellow Starfleet officer on this planet a godsend. While there was something odd and almost anomalous about the way Chekov had talked to him, at the moment that familiar Russian-accented voice was his only tie back to Tlaoli and the Enterprise.
But the more he thought about it, the more troubled Sulu found himself by Chekov’s presence here. He’d last seen the young ensign heading off into the Tlaoli karstlands in dogged pursuit of their lost captain, just minutes before Sulu had encountered the windstorm that transported him here. Even if Chekov had somehow gotten caught up in that same alien force, how could he have arrived on this planet so far in advance of Sulu that he not only had found a shuttle to fly, but also had learned the names of the aliens and the landforms and acquainted himself with strange technologies Sulu had never heard of? It didn’t make any sense….
Until Sulu remembered that Chekov was the one other person, besides Captain Kirk, who had previously been abducted by the strange alien force fields of Tlaoli.
Uhura had said the young Russian had been transported a short distance through the caves, and that nothing more had happened to him. But maybe that wasn’t true. Maybe the alien transportation device on Tlaoli sent everyone it caught to this distant alien planet. Or maybe—Sulu had an even worse but chillingly logical thought—maybe the alien transporter just sent copies of the people it caught. Sulu had met Chekov after he’d been transported through the caves, after all, and the Russian couldn’t have been both here and on Tlaoli at the same time. It was far more likely that he and Sulu had both been scanned and duplicated here, the same way Captain Kirk had been duplicated aboard the Enterprise a few months ago when the ship’s transporter malfunctioned and split him into two complimentary selves.
If his theory was right, Sulu thought, there should be a duplicate copy of Captain Kirk here as well. He repressed an urge to issue a wide-band call for the captain on his communicator, knowing it would be more likely to attract the attention of hostile aliens—these Gorn Chekov had mentioned—than to make contact with a man who might or might not even be present on the planet. He would mention his duplication theory to Chekov when the young man came to meet him, Sulu thought as he waved a veil of gnats away from his face. Then, if they really did seem to be just copies of their original selves, they could worry together about what to do next.
Sulu should have realized how much the soft pelting of the rain against the shuttle’s hull muffled any other sounds from reaching it, but he was so busy thinking about the unpleasant aspects of his duplication theory that the footfall he heard inside the cargo’s hold took him completely by surprise. He spun around in his pilot’s seat and started to get up, but the unmistakable snout of a metal weapon poked him in the chest before he could take a step. Sulu sank back into his seat, blood running cold as a scarred stranger’s face followed the weapon into the cockpit.
“You,” said the older man in a murderous-sounding but eerily familiar Russian voice, “are not Captain Sulu.”
“No,” Sulu said, when he could finally manage to speak. “I’m Lieutenant Hikaru Sulu, helmsman of the U.S.S. Enterprise.”
That answer, which he expected to be greeted by either a growl of rage or a snort of disdain, instead got him an impassive and intent stare. “Helmsman of the Enterprise?” the other man asked slowly. “Right now?”
Sulu glanced around the insect-filled shuttle and couldn’t restrain a small, wry smile. “Well, not right now. But usually, yes.” He glanced back up, trying to see past the gleam of the weapon to its owner’s shadowed eyes. “And you?”
“You don’t know me?”
There was no discernable emotion in that blunt question, but Sulu still felt a little guilty when he shook his head.
“I’m Commander Pavel Chekov, first officer of the Hotspur.” The older man lowered the weapon and took another step into the blinking glow of the cockpit’s instrument lights. Sulu tried hard to match his face to that of the young ensign he’d just met on Tlaoli, but between the ugly scarring and the gauntness, even the dark eyes barely looked familiar. “You’re younger than I remember ever seeing you,” Chekov said somberly. “So you probably don’t even know me yet. But twenty years ago, I was—or I will be—your navigator on board the Enterprise.”
* * *
“Lieutenant, hey, Lieutenant Uhura!” The distant shout from outside the walls of their shelter broke the strained silence that had fallen after Sulu’s final grim words. “Lieutenant, you’ll never guess what’s going on down in that ice cave!”
Uhura lifted a corner of an emergency blanket and felt a rush of cold cavern air displace the warmth that had built up inside the insulated space. The nano-fibers of her caving suit promptly expanded to compensate for the change in temperature, but she could see Sulu wince and hug his blood-stained camouflage jacket tighter around him with his left hand. Uhura motioned for him and Dr. McCoy to stay inside, then let the blanket fall behind her as she ducked out into the larger, column-filled cavern. It took her a moment to locate the glow of Sanner’s carbide lamp. It was dim as a firefly and far across the cavernous darkness, but it skipped and leaped toward her with the cave geologist’s typical energy.
“There you are! With all those reflective blankets you hung up, I couldn’t see anybody’s light….I thought maybe you guys had left without me.” Sanner condensed from a vague shadow beneath his helmet light into something so formless and white that he looked like a ghostly apparition floating toward her. Uhura peered at him as he got closer and saw that his cave jumper was thickly furred with extruded hoarfrost, as if it had gotten completely drenched and then frozen. His helmet was covered with a glittering rime of ice.
“What happened to you?” she exclaimed.
Sanner’s grin flashed in the darkness. “Just what would happen to anyone stupid enough to walk under a waterfall in the dark. I was keeping my light turned off as much as I could—”
“Get inside,” Uhura ordered, pulling the emergency blanket up and waving the geologist beneath it. He shed his ice-crusted pack as he went, then hunkered down near the little carbide heater and began stripping off his frozen gloves, talking the entire time.
“—since I figured I’d rather hit a rock, or even a waterfall than run into that alien force field without seeing it. Lieutenant Uhura, did you know there were blue emergency lights in all those alien conduits down there?”
Uhura finished resealing the tent walls behind her and came to join the others, settling down at a safe distance from Sanner and the pool of melt water already forming around him. “I noticed there were lights in the walls,” she said, remembering the eerie glow she’d seen during their tense retreat from the ice cave. She’d assumed it was part and parcel of the same mysterious force field that had swept away Captain Kirk and Ensign Chekov. Sanner’s more prosaic explanation, that the aliens who built and used this place would have needed to illuminate the dark corridors they made, had never even occurred to her. “Were they bright enough for you to keep your carbide turned off all the time?”
“Not really.” Sanner shed his helmet and shook shards of ice off the collar of his uniform. “Obviously. But I left the carbide turned off anyway, so I could spot that force field from as far away as possible.”
“Where was it this time?”
“I don’t know! I never saw it, because there was too much water running in the corridor to get down that far.” Sanner gazed expectantly across the tent toward Uhura, as if what he had just said should have meant something to her. Her face must have shown her blank incomprehension, because the geologist smacked his empty gloves across his knee as if that could pound the significance of his words home to her. What it actually did was splatter him with droplets of melting ice. “Water, Lieutenant! Running down the corridors, making a waterfall through the hole in the roof where that kid Chekov and Captain Kirk fell through….”
“Oh!” Uhura’s eyes widened as she finally realized what he meant. “The ice is melting! The caves must be getting warmer again.”
“Precisely, as Mr. Spock would say.” With a grimace, Sanner blew on his fingers. His bare hands were now wetter and probably colder than they had been before he’d stripped off his waterproof gloves. “This upper cave is the coldest part of the whole system now, trust me. I was soaking wet for fifteen minutes on the way back, but I didn’t start freezing until I was halfway up the spiral that leads here.”
“Stick your hands up your sleeves,” McCoy suggested. “That’ll get ’em dry again.”
“Thanks.” Sanner wriggled his fingers under the edges of his jumper sleeves, and a sheen of extruded water promptly appeared on the outside of the cloth as it wicked the cold water away from his skin. “The farther down you go toward the ice cave, the warmer it gets,” he told Uhura enthusiastically. “You can see by the way the fog’s building up down there that it’s the walls of the conduits that are getting warmer, not just the air flowing through them.”
“So what does that mean?” McCoy asked. “If you’re trying to convince us to stay down here and do some more caving, Zap—”
“No, no! This tells us something important about energy consumption.” Sanner waved his gloves for emphasis, scattering them all with ice-cold drops of water. “When I first heard how the Enterprise lost so much power trying to beam us out of here, I started to wonder what was going on down here, energy-wise. I mean, if this place really did have its own transperiodic energy source, it wouldn’t need to drain power from us, would it? It would create heat as a by-product, not cold, the same way dilithium crystals do when they generate a warp field. But instead, the temperature dropped every time we lost power down here. And I think that means Tlaoli is exactly as energy depleted as we first thought when we surveyed it. The only way the alien transporter can be activated is by stealing energy from any outside sources it comes into contact with.”
“Like the power cells in our tricorders and phasers,” Uhura said when Sanner finally had to pause to take a breath.
McCoy grunted. “Or the power storage banks of Enterprise, after it made contact with that transporter beam.”
“Anything with electrical currents flowing through it,” Sanner agreed. “I have no idea how the energy gets taken…maybe through some sophisticated sub-space magnetic fields, maybe some other kind of alien physics we don’t understand yet. But I’m betting that it takes that machine a long time to build up the energy it needs to activate a transfer. And in the meantime, it has to store its power somewhere.”
“That would make sense,” Uhura said. “But what does the cold have to do with it?”
“Isn’t it obvious?” Sanner said. “The energy storage reaction has to be endothermic, Lieutenant. The more energy that gets put into the system, the more heat the system absorbs from the ambient environment.” The cave geologist waved his gloves again, this time up at the shadowy rock ceiling that loomed above their sheltering emergency blankets. “That might have been okay a million years ago when this place was basking in sunshine, but now that it’s buried underground, it’s not so good. Rock is an awful conductor of heat, so nothing flows in to replace what the energy storage reaction takes out. The result is an instant deep freeze whenever the machine starts charging itself up.”
Uhura took a deep breath of comprehension. “Then when it starts warming up again… does that mean the device has taken its energy out of storage and used it?”
“Bingo!” Sanner rocked back on his heels, looking enormously pleased with himself. “Energy consumption has to be the machine’s limiting factor, Lieutenant! And the fact that it’s still getting warmer in the caves right now means—”
“—that the alien transporter used up all of its energy supply transporting me here,” Sulu said. The older man’s deep voice sounded composed and thoughtful, as if this scientific puzzle was the only thing he had to worry about right now. Uhura’s respect for this future version of Sulu was increasing the longer she knew him, as was her conviction that there must be more to the young helmsman she already knew than an easy smile and an enthusiasm for unusual hobbies. “It would need a tremendous amount of power to move someone halfway across the galaxy and backward twenty years in time—”
“—especially since it sent our version of Sulu back the other way!” Sanner finished triumphantly.
Uhura felt her stomach knot up. “We don’t know for sure that it did that, Zap. He may have just been transferred to some other part of Tlaoli—”
The scientist started shaking his head before she even finished her sentence. “Not according to my calculations, Lieutenant. I estimated how much power the transporter here could have absorbed from all our dilithium cells and from the Enterprise. God only knows how much power it takes to travel through time, but if you assume it’s an order of magnitude more than what it would take to go that same distance through space… well, the equation only balanced out if I assumed it was a two-way transfer and the shuttle got sent, too.”
“You’re forgetting that the alien transporter already used some of its power transporting Captain Kirk and Ensign Chekov,” McCoy pointed out.
“No, I’m not,” Sanner said indignantly. “It barely needed any power at all to move that kid Chekov around down here. Especially since if he skipped through time at all, it couldn’t have been by much. We’ve still got pretty much the same Chekov we started out with.”
“But probably not the same Kirk,” McCoy said. “And we won’t know where and when the alien transporter sent him until we find the version that got out of this cave and is wandering around up on the surface somewhere.”
“But the important thing,” said the older Sulu, “is that the warming of the caves suggests the alien device is no longer charged up or capable of transporting anyone, either to the future or the past. Is that correct?”
“I think so,” said Sanner. “I just wish I could have gotten down to the ice cave to make absolutely sure the force field was gone….”
“There’s another way we can check on that.” Uhura swung around to eye the pile of stacked crates and backpacks she had used as the tent’s third wall. One crate in the corner was marked with the Starfleet division symbol she knew better than any other in the service. She wrestled it out from the stack, making the tent sag a little in that corner, then threw open the lid to expose the small, portable communicator inside.
“That won’t work,” McCoy objected. “If the survey team brought it down with them, its power supply should be drained and dead now.”
“It is,” Uhura said, seeing the telltale darkness where a status readout should have blinked. She lifted the communicator out from the box anyway. “But we brought the last of Martine’s chemical battery packs down here with us. You didn’t use them for anything, did you, Zap?”
“Nope.” The geologist was already rummaging through his overloaded backpack. “They’re in here somewhere, probably all the way at the bottom. There we go.”
He handed the old-fashioned chemical battery to Uhura, who had already opened the communicator’s cover and pulled out the wires connected to its drained power supply. She twisted them around the terminals of the chemical battery instead, then took a deep breath and slid open the partition that let the old-fashioned chemical reservoirs come into contact and start the flow of electricity. She had no doubt that the alien transporter would soon begin to drain this power supply, just as it had drained all the others they had brought down into these caves. But, in the meantime, they just might have a chance—
“Uhura to Enterprise,” she said into the communicator, spacing her words for maximum clarity. “Come in, Enterprise.”
There was a pause whose pure silence seemed almost too good to be true, then Uhura heard the tiny click she was waiting for and began to breathe again.
“Enterprise here,” said Spock’s clear and familiar voice on the other end of the open channel. “A status report would be most welcome, Lieutenant.”
Uhura repressed an undignified urge to giggle at the austere hint of reproach coloring the Vulcan’s response. “Aye, sir.” She gave him a succinct explanation of everything that had happened since her last contact with the ship. “We’re still not sure what happened to Captain Kirk,” she said at the end. “All we know is that the Sulu we have now never served under him or knew him.”
Fear of losing her connection to the ship had made Uhura’s explanation so condensed that she wondered if even Spock’s superhuman intelligence could grasp all the nuances of it. She waited worriedly, watching the power supply indicator slowly decay on the communicator’s status panel, and finally heard McCoy grumble, “Come on, Spock, say something,” beneath his breath.
“Report acknowledged, Lieutenant.” The Vulcan sounded no different than he had a moment before. “Under the circumstances, it would clearly be too dangerous to beam anyone down to assist you, but we will send another shuttle as soon as possible. What do you estimate the current power supply of the alien transportation device to be?”
“Low, we think, but we haven’t been able to make a direct observation.” Uhura saw Sanner frantically flapping a piece of paper at her from across the tent and realized it was his topographic map of the overlying karst plateau. “Geologic Specialist Sanner has some information about where the danger levels might be highest.”
Sanner scuttled across the tent on his knees and bent over the communicator. “Bearing due south from the highest peak in the southern karst plain—” He rattled off a series of numbers and vectors that made no sense to Uhura. “—keep entirely clear of that area,” he concluded. “Have the shuttle approach base camp from the opposite side of the karst plain.”
“I believe I can pilot in accordance with those restrictions,” Spock said calmly. Uhura opened her mouth, but McCoy was already asking the question she intended to ask, a lot more incredulously than she would have dared.
“Spock, you’re not coming down here yourself, are you?”
“Certainly I am, Doctor.” That urbane Vulcan voice never expressed any emotion as palpably human as worry, but there was an undertone to it now that was at least reminiscent of that emotion. “There will be an unavoidable delay of approximately thirty minutes while Commander Scott installs magnetic shielding around the warp core and engines of a second cargo shuttle. During that time, you will gather all personnel at the survey team’s base camp so that we may begin to analyze and deal with the situation as soon as I arrive. That,” he added unnecessarily, “is an order.”
“Aye-aye, sir,” Uhura said, but McCoy wasn’t quite as easily intimidated.
“What’s the hurry, Spock?” he demanded. “Is there somewhere else we’re supposed to be right now?”
“No, but there is somewhere else that we currently are,” the science officer replied sharply. “And that Enterprise—the one that is supposed to exist at this time and place—has probably already been affected by the disruptions we have created in the timeline.” Spock’s voice became muffled as the chemical battery began to lose its electrical charge, but Uhura still had no trouble hearing the starkness in his words. “If something we have done has erased Captain Kirk from our own past, then the only reason we can remember him now is because we are floating in a bubble of disconnected time caused by our inadvertent slingshot at Psi 2000. And that bubble is due to rejoin the main timeline approximately fifty-six hours from now.”