Disclaimer: I do not own Star Trek or any of its characters. I'm simply writing this for fun, not profit.

Kirk knows what he's getting into. He knows it, but he doesn't like it.

As soon as the words are out of Spock Prime's mouth, he knows exactly how he can emotionally compromise Spock.

The mind meld is still painfully fresh in his thoughts, raw emotions threatening to overcome him as he chokes back the loss of six billion, four hundred thousand, eight hundred ninety two Vulcans. It didn't seem real to him, watching on screen as the planet disintegrated into nothing, massive portions of earth carrying away millions of lives until nothing remained; now, he can barely feel his own fingertips, his entire being rocked to its core as he tries to process so much life gone in a fraction of a second. It hurts, every breath aching in his lungs, keenly aware that among those lost were children, mothers, fathers, entire families.

Spock's family.

His father was spared. Kirk didn't need to ask what was happening to know that the unthinkable had occurred when Spock and four others beamed aboard the ship, one transporter platform noticeably empty. Spock's arm was extended, the distant echo of "Mother!" still ringing in Kirk's ears as Spock took two steps forward and stood, petrified and painfully real, in the space where she would have stood.

He cleared the platform so quickly that between one blink and the next, four figures stood alone, dazed, amazed, and reeling.

"My people," Sarek began, acknowledging his small entourage with quiet dignity as he stepped forward, echoing Spock's movement eerily as he finished softly, "require assistance."

Bones had been there in an instant. Kirk had never been more grateful for his presence, so out of his league that he didn't know how to speak anymore, didn't even remember to protest as Nurse Chapel – that's your name, right? Hi, hey. I'm sorry. It's been a while – led him away. He didn't know where to or what next, but one moment the bright lights of the transporter room were there, the next gone as he sat on the edge of a cot and let another nurse bandage his hand slowly.

He stared in mute fascination around the room, taking in six dozen refugees, his heart twisting as he realized that only half of them were Vulcan. And only one caught his attention fully, arresting him in breathless anticipation: Spock, seated on the edge of a biobed, back straight and eyes forward, hands motionless in his lap. He watched Spock, waiting for some unspoken acknowledge, some quiet disinclination to speak, but Spock didn't move, staring ahead and processing in blank, uncomprehending horror at what was.

And what had been.

Seeing what had been – that flicker of vivacity from Spock Prime's consciousness, of a Vulcan that outlasted him by millennium – makes bile rise in Kirk's throat.

He swallows, and tells him, "So you're saying I have to emotionally – compromise you?"

"Jim, I just lost my planet," Spock Prime reminds quietly, breath catching a little on the words, imperceptible to the untrained ear. "I can tell you – I am emotionally compromised."

I'm sorry, Kirk thinks, and he wants to crumple, to dissolve into tears and try to hold his own little world together (one in a billion), but he can't, because Scotty's there and he needs to get back aboard his ship if he wants to have a prayer at saving Earth.

Billions lost. Billions more.

He cannot cope with the loss of Vulcan – not in this way, not today, not forever, maybe – but he can save Earth.

He must save Earth.

So he agrees to it. Agrees to let Scotty dissect every single one of his molecules in an instant and propel them through time in space in a fraction of a fraction of a second, even though every instinct he possesses screams against it. It's not possible. No one can travel fast enough to catch up to a ship at light speed, because that's all warp is, underneath the technical jargon, all they're doing is playing with light and sound and tearing themselves apart to surpass them.

Looking across at Spock Prime, Kirk stares at him, heart pounding, and feels a sense of calm wash over, of certainty.

If Spock Prime exists – if Spock Prime is real – then maybe everything will work out. Somehow.

"Live long," Spock Prime says, holding up one hand in a salute Kirk has never borne witness to before, a lump thickening in his throat as he realizes how scarce such a salutation will be, going forward, "and prosper."

He dissolves into light, Scotty at his side.

It's a whirlwind from there, one moment standing on the solid decks of engineering, the next racing Scotty down the chutes in a frantic attempt to release him before he's torn to pieces by the filtration. It works – barely – and Kirk has a moment to thank God for quick hands before he's hauling Scotty to his feet and asking him if he's even alive after that.

"My head's buzzing and I'm soaked, but otherwise I'm fine!" Scotty sputters, face beet red and eyes bulging a little but otherwise alive, breathing, whole.

We made it. We made it on board the Enterprise.

The thought fills him with a sort of reckless euphoria – twice now he's sneaked onto this ship, this glorious, impenetrable ship – and now he has a mission to save Earth.

To save Pike.

One in a billion, he thinks, as he's lunging across staircases, halfway through engineering in less time than it takes to flip the warp core overrode switch when reality catches up to him.

"Halt!"

He whirls on his heel, instinctively seeking an out – just like a bar brawl, it's all a game – when Cupcake corners him.

"Come with me," Cupcake barks, phaser leveled – stun, stun, thank God it's stun – at his face as he steels his expression in rigid victory and adds, "Cupcake," as though the world itself will bow to his verbosity.

Kirk has enough class not to roll his eyes, but it's a near thing as he lets the security detail lead him away, Scotty at his heels.

They reach the bridge in record time and Kirk is surprised that it isn't the brig. You're losing your touch, Spock, he thinks, not uncharitably, as he and Scotty are forced to the center of the room.

Spock advances, black mood hanging over him like a cloud, and halts directly in front of them, violating every code of common courtesy as he demands, "We are traveling at warp speed; how did you manage to beam aboard this ship?"

It's easy, so easy, to reply, "You're the genius, you figure it out."

Spock's eyes twitch, narrowing, before he deflects, crushing Kirk's resistance underfoot as he turns to Scotty instead. "Are you a member of Starfleet?"

Scotty gapes at him, momentarily unseated, and Kirk has a moment to pity him – he doesn't know the half of it – before Scotty responds, "Um, yes – can I get a towel?"

"Under penalty of court martial, I order you to tell me how you managed to beam aboard this ship," Spock says, cool and irrefutable.

Scotty's halfway through "Well," when Kirk cuts in with a simple flat, "Don't answer him."

"You will answer me."

Kirk's never heard Spock's voice in that register. He can't honestly say if it's ignorance or extraordinary bravery that allows Scotty to say simply, "I'd rather not take sides."

"What is it with you, Spock," Kirk demands, pressing his advantage as Spock's eyes flash, every fight instinct rearing in pursuit of new prey. Don't go after him, Kirk thinks. Come at me, Spock. You know you want to. "Hm?" He steps forward, crowding Spock's personal space, aware of Spock's every shallow, heated breath as they stand, toe-to-toe and unyielding. "Your planet was just destroyed, your mother murdered – and you're not even upset," he says softly, almost a taunt, and he can almost hear Spock's attention click into place, his target set.

Attaboy, Spock, he thinks, heart rate escalating. Let it go.

"If you are presuming that these experiences in any way impede my ability to lead then you are mistaken," Spock retorts.

"And yet, you're the one who said fear was necessary to lead – did you see, his ship, did you see what he did?" Kirk demands, unwilling to be daunted by Spock's awareness of his strategy. You might know what I'm up to, he allows, that doesn't mean you can stop it.

"Yes, of course I did," Spock grits out.

"Then are you afraid or aren't you?" Kirk asks, cold, flat, stepping closer still as Spock regroups enough to say, "I will not allow you to lecture me on the merits of emotion."

You'd better be right, you pointy-eared bastard, Kirk has enough time to think as he takes one clear step closer before replying, "Then why don't you stop me?"

Spock's gaze is ruthless. "Back away from me."

"What is it like," Kirk expounds, including the entire bridge crew without once addressing them, opening the board to humiliation and frustration alongside Spock's anger as he demands, "not to feel anger, or heartbreak? Or the need to stop at nothing to avenge the woman that gave birth to you?"

"Back away from me," Spock repeats, cold and deadly quiet, and Kirk rises to the challenge, shouting in his voice, screaming at him because son of a bitch I will not let you win I will not let Pike die I will not let Earth be destroyed.

"You feel nothing. It must not even compute for you. You never loved her!"

Spock lunges at him. Kirk's ability to think rationally crumples in an instant.

. o .

Later – once the waves have settled and the day is done – he will remember those moments.

Spock's fist shot out so fast it almost broke his nose. As it was, it fractured the orbital bone protecting his left eye, effectively blinding him in one eye as pain swept over him. Through the ringing in his ears – Bones confirmed a mild concussion in the same shot – he registered being pushed forward, thrown back into the melee by the same security team that he would later congratulate for a job well done, for a good day's work, for protecting them.

None of the bridge crew intervened; it isn't fair to single one party out more than another. They knew – in the same way that Kirk knew it would end this way, that it had needed to end that way – and they did not interfere.

(It isn't until Kirk is done saying his spiel to the entirety of the security team –dismissed, gentlemen – that those three advance, much later, to speak with him.

Cupcake is the one to step forward and tell him that he couldn't hold him back. And he tells him, in a low voice for Kirk's ears alone, that he is sorry.

Kirk puts a hand on his shoulder and assures him in an equally quiet voice that it's okay.

Cupcake accepts that, and Kirk knows that it is the truth. Had he resisted, he would only have been caught in the crossfire. Better to let Spock run rampant than get trampled by him.)

He thinks that, maybe, that was the moment when he and Cupcake became something akin to kindred spirits, united by a common love for their work, and a mutual understanding of its dangers.

Spock was dangerous, then.

Never before had Kirk classified Vulcans as a hostile species. He knows that they are related to Romulans – distantly; our species share a common ancestry – but it doesn't compute with him that Vulcans are capable of the same scale of violence.

How very wrong he was.

Fear took over at some point, he recalls, between being flung and grabbed and shoved against the hard back of the command chair. He lunged forward, hoping to incapacitate, and his fists bounced harmlessly off Spock's arms, solid steel underneath his uniform, his muscles rippling with cool precision as he batted Kirk's hands away and went after him.

Spock got him half a dozen places – he has the black-blue bruises to prove it – before Kirk flung his arms over his head, wrists locked in a defensive position, every ounce of tactical training rushing through his veins as he tried not to lose his footing.

He realized – too late – that he couldn't hope to hold Spock back, and the pain that exploded in his wrists as Spock broke them apart strangled him.

Whatever he'd meant to do – whatever he could possibly have said – fractured as Spock nailed him in the sternum, hard enough to bruise bone as it winded him, pressing forward and nailing him at the base of the throat.

For one terrible moment, Kirk was certain he'd crushed his windpipe. Clutching his throat, he righted himself, desperate for breath and disoriented, barely aware of Spock's presence as his world narrowed down to those fists.

Spock backhanded him across the face. The bruises took hours to form.

Then he grabbed him by the throat and strangled him.

Kirk shivers as he reaches up to rub his throat reflexively, wondering if it was worth it.

I had to get control of the ship, Kirk reminds himself, staring in the mirror at his own ragged appearance, smiling wryly at the marked lack of bruises. Beauty of modern technology.

His computer chimes, informing him that someone is requesting entry to his quarters. Frowning, he stands and approaches the door, straightening the blacks of his 'uniform' as he presses the entrance sequence, almost falling back in surprise when he sees Spock.

"What are you doing here?" he asks warily.

"Dr. McCoy informed me that you would be here," Spock replies calmly, unfazed by Kirk's surprise. "Permission to enter your quarters?"

Kirk licks his lips and considers telling him no. After a moment, he nods, stepping back.

Spock is dressed in grays, signifying a higher rank as he comes to a halt in the center of the room, turning briefly to face the windows overlooking San Francisco bay. Kirk follows his gaze and feels some unspoken tension mounting between them, the need to speak caught in his throat before he forces the words out.

"I'm sorry."

Spock's shoulders tense. He does not move.

"I acted inappropriately," Kirk elaborates, tucking his hands behind his back and linking them, staring outward, peripherally aware of Spock's presence. "I should have told you."

Spock inclines his head slightly and says nothing. Compelled by the permission to continue, Kirk says in a low, serious voice, "I'm so sorry, Spock."

A beat of silence passes. "Apology accepted," Spock says quietly, unmoving.

Kirk looks at him and reaches out compulsively to rest a hand on his shoulder, giving it a light squeeze. He knows that if the contact were skin-to-skin he would feel an echo of Spock's thoughts, suddenly, overwhelmingly aware of that tangibility.

Spock's muscles bunch underneath his fingers as he stiffens, but he refuses to move away.

"You did everything you could," Kirk utters, almost inaudibly.

"I did not do enough," Spock says, simple, irrefutable evidence that Kirk knows must be torturing him. The curse of those gifted with the ability to shut down emotions and reign on logic alone: logic is unforgiving.

"We avenged her," Kirk insists, and Spock's head bows incrimentally in acknowledgement. "That's enough, Spock. For her, that's enough." Releasing his shoulder, he steps back, adding, "She would be proud of what you did." A beat, and then, "You did good, Mr. Spock."

Spock's gaze flicks to him, black and unreadable in the dark. Lights, eighteen percent, Kirk remembers ordering upon entry, an ambiance of seclusion he enjoys, a healing dark. With the soft light from the bay trickling in, it illuminates the shadows of Spock's features, making him appear cut from something far stronger than flesh and bone alone.

He wonders what Spock sees when he looks back at him – maybe the frailty of Human life, so very breakable under his hands, or the presumption of those that dare to defy his own perception of life. Whatever he sees must reassure him, somehow, because his features relax, briefly, and Kirk sees the echo of Spock Prime there, humble and secure, knowing that all is well.

It will be, Kirk amends.

"Thank you, Captain," is all Spock says, turning on his heel and departing without another word.

Kirk doesn't follow him, letting him go and breathing easily for the first time in days.

We're not friends, he thinks, settling on the edge of his bed and staring out the window towards the bay, gaze drawn inexorably upwards toward the night sky where space awaits, wondering if he'll ever see it again from the captain's seat.

They still haven't ruled on it, and Pike refuses to say anything about it despite his release from Starfleet Medical to active duty two days prior. Bracing for the worst, Kirk looks over and see the tiny model Enterprise Pike left him, gently lifting it and dusting off a new sheen that's coalesced in his absence. It was a hell of a ride, he thinks, and is glad that he made it.

Still. He knows that his business is unfinished as he rises, staring out the window at that indefinable space, wondering how far it goes, how far he can reach, and who he can take with him.

Wordlessly, he resolves to make it there. Even if he must submit to the lowliest of positions aboard a starship, he will do it, so long as he can catch a glimpse of that from the other side.

Yet he has seen the consequences, too, and it makes his torso ache anew, an entirely different pain residing in the hole in his heart.

Earth is still here, but Vulcan is gone.

I won't let it happen again, he decides, setting down the tiny Enterprise and looking out for the real one far, far above. And I will never use that pain against him again.

. o .

"Permission to enter your quarters, Commander?" Spock requests quietly, eight months later, and Kirk makes an ambivalent gesture with one hand, back to him as he steps inside the room.

"Granted," he echoes, hollow, his eyes aching and his throat dry. "What brings you here, Mr. Spock?"

Spock seats himself on the edge of Kirk's bed and does not reply. "We will avenge him," he promises, simple, fortifying logic in the midst of Kirk's emotional storm almost soothing.

"We will," Kirk echoes quietly, folding his arms as he stares out the windows, every bone in his body aching with loss. He's known the risks of captaincy for so long that it feels like centuries have passed in the course of eighteen months. Ever since he was appointed captain of the Enterprise, it's been nonstop, a whirlwind of challenges and criticisms. The brass doesn't trust him because regardless of how closely he follows their rules, there is always one he must object to, one he must defy, and it is those moments that define him in their minds.

He is the rule-breaker, the game-changer.

Yet when the took his ship away from him, there was nothing he could do. No amount of arguing with Pike, no amount of Please, sir.

Pike invited him back. Pike gave him one last chance.

And now Pike's dead.

Breathing in slowly through his nose, attempting not to suffocate on his own grief, he remarks quietly, "I don't know how you survived, Mr. Spock."

Spock rises, approaching until he stands shoulder-to-shoulder with Kirk, looking out over the bay once more, unchanging, unmoved. "I have a purpose," is all Spock says. "One which I cannot refute or ignore. That purpose is to live."

Or die, Kirk adds silently, and the fragility of it all astounds him.

Part of him wants to hide away, to ignore reality and pretend that it does not exist. Reality is dangerous: reality is pain and suffering and, ultimately, death. He wants to curl up under the nearest rock and never emerge again, never face the same trials and tribulations of love and loss again.

But Spock is there, and Spock is right. He cannot. He will not.

Not while there is something to do.

"Purpose," he echoes, tasting the word, savoring it. "Is that the answer, Mr. Spock?" he asks, curiosity lacing his tone as he tilts his head in Spock's direction, not looking at him.

Spock is silent for several long moments, considering. At last, he replies simply, "I believe so."

Kirk nods, and does not restrain him when he chooses to leave.

Purpose.

. o .

It isn't until he is dying of radiation poisoning that he realizes what it is.

It's not purpose that keeps us going, Spock, he thinks, unable to form the words as he presses his fingers against the glass separating them, hot and raw and uneven, breaths already deepening and sinking in his chest, unable to pull in enough air. Purpose isn't enough.

For he has fulfilled his ultimate duty, his final purpose in life and still he is afraid. Still he regrets, and still he begs Spock to save him.

It isn't purpose, he thinks, his dying breaths slowly fading as the world begins to dissolve around him, Spock's fingers the last solidarity as he reaches for them, wishing he could grasp them, cling to them, to life. It isn't purpose, Spock.

It's love.

When he dies, he is grateful that Spock knows: Because you are my friend.

. o .

The world is far brighter than he remembers when he awakes.

Awake, in pain, yet ardently, electrically alive, he listens to Bones ramble, to Spock's halting, formal speech, and tells them both that he loves them.

Somehow, without ever saying the word, he knows that they hear it, and he knows that they are grateful.

I couldn't lose you. I couldn't leave you. I couldn't let that happen to you.

I couldn't let you experience that pain again.

Bones leaves Spock and he alone at some point, and though consciousness is tentative and his clutch on reality slim at best through the haze of drugs, he has a point of clarity in the dark room, on the gray uniform clinging to Spock's shoulders.

Profoundly aware of the unbidden strength beneath those shoulders, Kirk extends a hand in mute supplication.

After only a moment's pause, Spock steps forward, easing himself into the sole chair in the room beside Kirk's bed.

Kirk closes his eyes briefly, breathing out slowly and just listening to the tiny, barely there sound of Spock's own warm, even breaths nearby, and thinks, I'm glad you're alive.

"You did good, Spock," he says. "You did good."

Spock doesn't respond, doesn't even correct his grammar as he reaches out and closes his hand, very gently, over the back of Kirk's. A warm pulse of relief thrums there, barely noticeable and somehow inarguable, as Spock replies simply, "Thank you, Captain."

They stay like that for a long time, and when Kirk drifts off to sleep, Spock is there.

Just two in a billion, Kirk thinks, consciousness fading. Two in infinity.

And yet somehow - inexplicably - worthwhile.


Author's Notes: I am absolutely fascinated by the relationship between Spock and Kirk.

Thank you for reading, I hope you enjoyed! Closing in on the collective 700,000 word mark. Thank you for welcoming me so warmly into the Star Trek community; let me know if you have any prompts, requests, or suggestions, I'm always interested.

Thanks again.

~truffles