A/N: I felt like writing this. So I did.

Like a Heartbeat

Kirk has always been kind of a flashy guy. He came into the world in the midst of explosive destruction and he hasn't done anything half-assed since then.

When he falls in love, it's like fireworks; exploding into being only to fade away in the same instance. For a couple of weeks it's all grand gestures and passionate declarations, before it inevitably dissolves into nothing. And it's not that Kirk means to leave a trail of broken hearts in his wake. It's just that every time feels like it's going to last forever and he's always caught off guard when it doesn't.

But nothing has caught him more off guard than this thing with Spock. Because with Spock, it doesn't happen like it's supposed to. There is no epiphany, no sudden realization. It doesn't come fast and it certainly doesn't come easy.

It starts, fittingly enough, on the bridge of the Enterprise, during the Narada crisis. That's where the first spark is lit, the idea that maybe he and Spock could learn to work together. That they might even make a good team. By the time they're limping back to earth, battered and just a little bit broken, Kirk knows they do. On some instinctual level, they just click perfectly. It's great for emergency situations but it doesn't translate quite as well into the day-to-day challenges of running a successful starship together.

Kirk learns this when they first ship off on a five year mission, with him as the official Captain of the Enterprise and Spock as his First Officer. Kirk doesn't know what possessed the Vulcan to accept the position but he couldn't be gladder for it. His good cheer is somewhat dampened during the following weeks, when it seems Spock is doing his very best to piss Kirk off by criticizing every little thing he does. It takes a little while for Kirk to stop feeling persecuted and recognize the situation for what it really is - that Spock is just as unsure as he is.

He calls Spock into his quarters and they spend hours talking. At some point, it stops being ship business and turns personal. By the time Spock leaves Kirk's quarters, they've gained a new understanding of each other.

Kirk may not realize it yet, but it's already past the point of no return for him. Maybe it has been since he decided to entrust Spock with his life on the Narada.

From that day, they develop a tentative friendship along with their budding working relationship. One day, Spock reveals that he plays chess and just like that, they've found common ground. Things start to run a little bit more smoothly.

Throughout all of this, Spock is still in a relationship with Uhura.

Life goes on. Or it does for most of them.

It only takes five weeks for the first crewmember to die under Kirk's command. Kirk has no idea how to deal with it. His first instinct is to seek out Bones, but Bones is busy saving lives. Kirk staggers back to his quarters, feeling helpless and absolutely miserable. All of a sudden he feels the full weight of the responsibility that comes with his position, and it is suffocating.

Spock saves his life that night and how he does it is very simple. It doesn't take more than a few words, uttered through the doors of Kirk's quarters because he refuses to let Spock in:

"Captaincy is a highly demanding position. It would be a cause for worry if you did not occasionally find it a difficult burden to bear." A pause. "You are an excellent Captain, Jim. You are also my friend."

That's it and that's all it takes. Honestly, Kirk would have been fine if it had just been that one word. Jim. Spock has never called him by his given name before. Somehow, it feels monumental.

Kirk never gets used to losing a crewmember, but he learns to live with it. You've got to take the bitter with the sweet.

It is eight months since they shipped out, and Kirk finally gets around to contacting his mother. They haven't talked since Kirk left earth last, which for them isn't all that unusual.

Winona looks exactly like Kirk remembers her. Her features are youthful, although some wrinkles have begun to appear, and her hair is golden, admittedly with a grey strand here and there. Kirk is beginning to doubt she'll ever really grow old. He secretly thinks it might have something to do with his father, that if Winona can't grow old with him then she'd rather not grow old at all, but it's a fanciful idea and not one he takes particularly seriously. Spock would think him crazy if he ever told him.

Sometimes Kirk wonders whether Winona would still love George so fiercely if he were alive. After all, he takes a lot after his mother. They both love recklessly and selfishly, with too little regard for who they may hurt in the process. It hurts Kirk's heart to think like this, though, so he never dwells on it.

Winona has nothing important to say or if she does, she's not saying it to Kirk. Their comm call is short and awkward, with little information shared on either part. When Kirk hangs up, he finds himself longing for a genuine conversation. He somehow ends up at Spock's door and they spend the rest of the day playing chess and talking.

With Spock, Kirk doesn't have to be careful in what he says. There's nothing he could blurt out that he doesn't want Spock to know.

Their friendship continues to evolve and with it, something else emerges. Neither of them knows what that something else is, or are even aware of its existence, but it's there and it's growing.

When Kirk's not working, he's usually with either Spock or McCoy. Spock, meanwhile, divides his time almost equally between Kirk and Uhura. He spends most of his evenings in Kirk's quarters, playing chess or discussing recent missions, but then he inevitably returns to his own quarters, where Uhura is usually already asleep in their bed.

It hurts Kirk to think about it, but he's not sure why. He's started to develop a dull ache whenever he sees Spock and Uhura together and it takes him a long time to realize that it's jealousy. It's a different kind than he's ever felt before; before it was sharp and all-consuming, but now it's a constant, empty hurt right in the core of him that's a thousand times worse.

Kirk isn't sure what to make of it but he thinks it might be because he's lonely. He longs to be in a relationship of his own, to have someone to return to every night, but it's not a specific someone. It's been a long time since he's felt that kind of fire or even a spark. Maybe it's because of his new position, maybe he can't give his heart to anyone because it already belongs to the Enterprise.

For almost a year, Kirk goes on believing that.

Then it's the third year of their mission. They've discovered more than they thought possible and made contact with countless new civilizations. They've risked life and limb again and again, all in the name of the Federation.

Kirk has never been this fulfilled. He's also never been this empty. He walks around with the constant impression that there's a part of him missing. As he grows older, he also grows lonelier. Or perhaps he merely grows more aware of his loneliness. It's hard to tell.

There's also that thing with Spock, that's been bothering him for a while. He can no longer say with certainty what Spock is to him.

One night Kirk is finishing up on a report. It occurs to him as he's tapping the stylus against his lips that he may be in love with Spock.

No, there's no may about it. He is in love with Spock.

Kirk can't call it a full realization, because at this point he already knows. It's probably not even the first time he thinks it outright like this. But it is the first time he thinks: what now?

The obvious answer is to shut up about it. After all, Spock is in a happy (as far as Kirk knows) relationship with Uhura, and has been for almost three years. He and Kirk have a great working relationship going, as well as a friendship that is immensely precious to them both. It would be stupid of Kirk to disrupt the status quo for the tiny chance that Spock may love him back.

But no, Kirk has to tell him. Not out of some misguided hope that Spock will leave Uhura to be with him. Kirk already knows that would never happen. Rather because up until this point, they have never thought to conceal anything from each other and Kirk's not about to start now.

Which is why, the next time they're alone, Kirk looks at Spock from across the table and simply states:

"I'm in love with you."

Spock, who has been staring intently at the chessboard, looks back up at Jim. There is surprise evident in his eyes. "You-"

"I'm in love with you," Kirk repeats. He's quick to add; "But don't feel pressured. I'm telling you this because we've always been completely honest with each other. I don't expect you to love me back or to leave Uhura for me. I know better."

Spock doesn't say anything and the dull ache in Kirk's chest grows just a little bit stronger, but he ignores it. He already knew how this would turn out and he knew it would hurt. Still, when all is said and done he is surprisingly okay with it. He's still jealous but that part of him is overwhelmed by the part of him that just wants to see Spock happy.

Because this thing with Spock, the love he feels for him, is completely different from anything he's felt before. It happened gradually and quietly took over Kirk's life, so now he can't ever picture himself without Spock by his side. It's nothing like fireworks or a rollercoaster ride or any of those things Kirk used to measure his love by. It's just there, inconspicuous and unassuming, yet as much a part of him as his own heartbeat.

If Spock is happy with Uhura, then that's alright.

"Lieutenant Uhura and I have terminated our relationship."

Kirk's snapped out of his thoughts. "What?"

Spock looks perfectly unruffled "Two point three weeks ago. I regret that I did not inform you of this sooner but my mind has been preoccupied."

Kirk is flailing. He already knew how this conversation was going to go, and he had accepted it. Now Spock has gone completely off-track and Kirk isn't sure what to expect anymore.

"Why?" He finally asks.

"She was restless," Spock explains, "and I unfulfilled. She wished for someone whom she could share herself with completely, while I already had someone else who filled that role perfectly." His eyes are dancing. "You, Jim."

And then he stands up, encircles the table and bends down, lowering his lips to meet Kirk's. Kirk closes his eyes instinctively. The first touch is warm, like coming in contact with sunlight after months of darkness. That warmth travels down to Kirk's chest and spreads through his entire body. By the time Spock draws back, Kirk is grinning like an idiot.

"You love me," he says happily.

Spock grasps Kirk's hand in his. "I do."

"Say it." Kirk needs to hear it, needs to know that he's not somehow mistaken because moments ago, he was certain that Spock would never be his.

Spock leans in closer, lays his forehead against Kirk's. He might be smiling. "I love you."

Kirk closes his eyes and holds onto Spock's hand as if it's the only thing tethering him to reality. And maybe it is, because at this moment, Spock is his reality.