On the bridge, the Kira-replicant saw a tiny orange light blink on in the top-left corner of her screen. Dax is finished, she realised, and she called up the appropriate interface data on the console in front of her. This was the critical moment: Dax had altered the ship's course, and hopefully Worf had made himself useful and rigged up the cloaking device. Now all she had to do was set the terminal network connections and hope for the best. She touched the keypad, nodded once to herself, and laid her right hand on the holstered hand phaser at her waist. That was only there if one of the parallel-universe crewmen decided to jump her. It was a violent option, but she had been born into a violent reality, and things had come too far now to be shut down like this.

The effects of their combined handiwork began to become obvious after a moment or two. More and more of the viewscreen became absorbed in the blackness of space as Jeraddo slid to one side, and she watched Dax note the slight drift, tried to compensate. But the hacked modifications should have taken care of that. And they had. The Dax at the helm looked over her shoulder at Captain Sisko. "Ben, we're drifting off-course and the helm's not responding."

Kira tried not to look guilty.

"Computer, run a level five diagnostic on the helm controls," Sisko said.

"Diagnostic complete. No errors to report."

"Is it a viewscreen malfunction?"

Jadzia looked down at the screens and shook her head. "All sensor nodes are operating normally. It's not overly serious, in that we're still in the shadow of the moon, but…we've almost completed a full circle. Shall I shut down the thruster array?"

Sisko paused for a second. "Yes."

The Trill tapped her controls. "Thrusters not responding to commands. Bridge to engineering. We've got a problem up here."

"What is it?" the disembodied-yet-impatient voice of Chief O'Brien asked.

"Helm, navigation, and propulsion have all been locked down."

"Nonsense! All diagnostic results show…"

Dax rolled her eyes. "Then the diagnostics must be wrong, because the ship just turned itself around." A blinking indicator on the helm screens caught her eye. "I…that's interesting. The thrusters just went back to standby mode."

Three…two…one…the Kira-replicant thought slowly.

"Bloody hell! The cloaking device switched itself on!" O'Brien cursed. The lights on the bridge winked out and consoles brightened. Dax looked down at her controls, not touching anything, as though the Defiant might bite her if she tried. Sisko got up from his chair and paced to the helm, but before he could get there, the voice of the computer said, "Warning: unauthorised modifications to cloaking device. Cloaking field is destabilising." The captain frowned and waved to Dax. "Shut everything down! Take main power off-line."

"Nothing's responding!"

"Cloaking field instability at nineteen percent," the computer droned.

"O'Brien! Shut it down! Now!"

"I'm trying, sir, but there's some kind of override in effect! I can't even get a peep out of her! I could manually take the warp core off-line, but…"

"Chief, if we keep going like this, we'll be discovered. Switch to backups and override the main systems before…"

Too late. Stars blurred on the screen, and the Defiant tore into subspace like a demon out of hell. Sisko sat back in his hair and watched as his ship slowly wrested its will back from the crew controlling it. He half-expected something else to happen, but fortunately, the Defiant settled into warp seven and shot out of the Bajoran system. The only problem now was how to get home. "Belay that, Chief," he said wearily. Forcing any warp core off-line without safeties while in faster-than-light speed was a suicidal exercise in itself, but with the four-lobed monster throbbing away in the engine room, it would have spread a trail of destruction across billions of kilometres. The Defiant had brought them home safely before, and the crew could now only hope that it would do so again, even in its possessed state. "Starships don't just start controlling themselves. If I were a suspicious person, I'd say that we've got a saboteur aboard."

Damn, he's quicker than I remember, the Kira-replicant chided herself.

Sisko frowned deeply. "Computer, begin a level-three anti-infiltration diagnostic on all computer functions. Trace unauthorised computer access and report to my console only, silent alert. Confirm identification through fingerprint scan for results."

"Acknowledged. Beginning level-three automated anti-infiltration diagnostic."

The Defiant's computer systems weren't the most advanced in Starfleet by far, but there was still a chance that the Dax-replicant's hacking efforts would be picked up by an automated search. The Kira-replicant settled back onto the uncomfortable stool and watched the dark-skinned human sit and wait. That was one of the things that distinguished him from his deceased counterpart. The Captain Sisko she knew had been constantly on his feet, pacing and making suggestions and always moving. He had been one of the lucky few who had raised a stable family within the unstable confines of the Federation as it collapsed around them: Jennifer Sisko was a research officer, and his son Jake worked with his mother on low-security issues. Of course, the term 'low-security issues' was becoming obsolete as the Borg slowly nibbled away at the borders of the Alliance. But it had been one of the few things that had remained solid after the takeover of Earth. Ben Sisko had sworn that even if the whole universe came crashing down, he'd put his family above his career, and he had. But then Ben Sisko had been ambushed as he tried to defend his outpost. The Kira-replicant sat for a moment and wondered how many Borg the tenacious captain would have taken down before he had succumbed to the metallic limbs and nanoprobes. Without a weapon? Four, maybe five, she concluded. He had trained himself in some kind of hand-to-hand combat, like most officers did now that the effectiveness of phasers was a subjective matter. She had watched him working out once or twice, and realised that his roundhouse kick would be enough to snap the necks of most humanoids, including all but the strongest of tactical drones. But that hadn't been able to save him, else he would be standing with her now. One more officer who was either dead or working for the enemy.

"Dax, show me our trajectory on the viewscreen," Sisko said, snapping the Kira-replicant out of her reverie.

The Trill complied without replying. A small representation of the Defiant blinked into existence on the curved wall screen, hovering over a grid that was scrolling beneath it. A green line appeared at the nose of the starship and shot ahead of it. "I'm running it against our own star charts," Lieutenant Dax said over her shoulder. "If things aren't too different in this reality, I might find an intersection point."

The Kira-replicant shook her head once, minutely, so that no-one else could see. When one had been fighting a war against a race of computerised humanoids, one learned to make one's plans not quite so obvious as that. If the Dax-replicant was half the hacker she seemed to be, she would have plotted a course that would take them somewhere inconspicuous, then change course again, and perhaps even a third time, before she would bring them to their destination. Her suspicions were confirmed when Dax informed them that they would not arrive near any planets on their charts. The Kira-replicant had worked with her colleagues to figure out a safe way to their journey's eventual conclusion. They would arrive in a dark nebula, change course, go back into warp, stop in the shadow of the desolate class-T planetoid of Beta Myamid, change course a second time, and go for the last thirty minutes before coming out of warp for the final time.

"O'Brien, this is Sisko. Is the cloak still functional?"

"Aye, captain, but there's some kind of…device clamped to the generator. It's emitting some background chroniton radiation. I don't know how it's affecting us. We seem to still be underneath Borg radar, though, so I'm not game to touch it until we're in a safer position. Are we still hurtling into the unknown?"

"Unfortunately, yes. It appears that someone hacked into the computer core and toyed with our helm and navigation protocols." Sisko paused, and then he said something that the Kira-replicant hadn't been expecting. "We've tried a soft reset of the computer, and that was already locked out. What if we do a hard reset?"

They hadn't thought about that. Performing a hard reset on the computer core would result in a shipwide loss of all non-vital systems. The secondary processor could handle the handful of essentials — life support, limited tactical functions, and a few other functions — but everything else would be interrupted. The Kira-replicant hadn't checked if the cloaking device would lose control if they did a hard reset, but she figured that it probably would. The Borg maintained several long-range sensor nodes that might detect them if they lost the cloak. If Sisko went ahead, he could most likely erase Dax's program (which was, for stealth reasons, stored in the computer's temporary memory partition) and shut down the cloaking device for up to a minute. In doing that, he would compromise everything that the replicants had worked for.

O'Brien had sighed at the question. "Sir, hard resets are only used in drastic situations. I mean…we could purge each partition of data added within the last two hours. That might solve the problem."

"I think our saboteur will be prepared for such an obvious solution."

"We'll also lose everything but life support for anywhere between a few seconds and a minute before the computer kicks back into gear. That means main power, shields, weapons, cloak…"

"This counts as a drastic situation, Mr. O'Brien. How many times have you heard of a starship that took control of itself?"

The engineer thought for a moment, then said, "Well, sir, the Enterprise did that once or twice. But it wasn't this kind of sabotage." He sighed the sigh of a man who had been prepared for an easy afternoon, then had a pile of work land right in his lap. "Can we put it off until we're in a safer position, sir?"

"Who knows where the Defiant will take us? I want control of my ship back, and I want it back now."

"Very well. I'm heading down to the core now. Give me a few seconds."

The Kira-replicant looked down at her console and saw a blinking orange light. That meant that the Dax-replicant was experiencing difficulty with some part of the operation.

"Alright, sir," O'Brien drawled. "I'm in position. Counting down from ten…"

The Kira-replicant tensed.

"Nine…"

At the helm, Dax locked all the temporary information they had gathered and downloaded it to isolinear backup. After the reset, she would restore it and the helm/ops station would continue just as it was. Other officers did the same.

"Six…"

Sisko showed no signs of backing down.

"Four…"

Colonel Kira Nerys, seated at Tactical, seemed to stiffen. It was as though some inner voice had told her to look over at her alternate universe counterpart. Their eyes met, and the Kira-replicant was forced to look away. She couldn't allow their plans to be foiled now. Not after all the information-gathering, all the worrying. They had been handed an opportunity that was certainly sent from the Celestial Temple, and she wasn't going to give it up.

"Three…"

Captain Sisko suddenly felt something cold press against his naked scalp. He turned to see the replicant of Colonel Kira holding a Bajoran hand phaser, the muzzle firmly pointed at him. She had a kind of strange compassion in her eyes, but behind it was a knife of cold determination. "Pause countdown!" he cried, his gaze never leaving hers. O'Brien heard and stopped just before he said 'two'. Silence reigned on the bridge, until Sisko finally had the courage to ask her one question.

"Why?"

She knew the answer to that one. "Because you can save us."