Destiny is falling asleep around him, all the corridors and the lights swinging into orbit around the cold dreamers at her heart. Young adds a line or two to his letter to TJ, wishing her all the joy he has singularly failed to give her. It's goodbye, and he lingers over it, rubbing the paper between fingers and thumb as he folds it. Her future is with a man who makes her smile.

His is... His is short. And he's fine with that.

Better than fine, to be honest. He has it planned. He'll walk out under the shattered hydroponics dome and let the last of the bad air sweep him out to be vaporized against the shields. Better that than to blow his brains out and leave a body for someone to find, half decayed, half frozen, three years later.

The thought of death is a weight lifted from his chest. Tonight he can breathe deep. He intends to enjoy it for as long as he's got.

The hollow knock at his door makes him hide the letters beneath the paperwork on his desk, embarrassed to be seen doing anything so sentimental by Rush – because it is Rush. Of course it is.

He has to come close to open the door, close enough so that as Rush brushes past him to come inside, they almost touch. Young cannot be in the same room now without being conscious of the physicality of Rush – the way he moves, the way he smells, all electrical snap and sharpness. Can't look at him without remembering what it feels like to have Rush struggling against him. He knows exactly how much effort it takes to overwhelm the man, to put him out and have him lie completely defenceless in the crook of his arm.

It's an odd sort of intimacy, primal and physical as the intimacy of sex, tying them together in much the same way. He will never again be so separate from the man as he was before he almost killed him.

Another responsibility he feels sure he'll be glad to shed. "Rush. What can I do for you?"

"Time's almost up," Rush looks around his quarters as if he's seeing them for the first time. "The pod's not going to be simple to fix. It may not be possible to fix it at all. To maximise the time available for repairing it, I suggest that the final two pods should be used at once. Then I will stay out and repair the last."

"Or die trying?"

Rush gives him a sidelong twist of a smile. "Exactly. You must admit, I'm the most qualified to solve this problem. I'm the one who understands Destiny's systems best. If anyone can do it, it will be me."

Which is certainly true. But Young is suspicious – it's not like Rush to volunteer for anything potentially life-threatening. He values himself too highly, considers himself an indispensable resource, without which the mission and the crew will be put in jeopardy.

He's right about that. So then why would he offer this now?

Young folds his hands in front of him, considering. He's glad they are both agreed that Eli's place is guaranteed. "You must admit that out of the three of us, I'm the most expendable."

He expected Rush's smile to widen, but it falls and what's left is a little like regret. "You say that because you want it. You want to die. As long as I've known you, you've been looking for a chance to give up."

This is also true. Young has managed to conceal it from the staff psychologists, but everyone else cottoned on a long time ago. Scott's appointed himself Young's personal suicide prevention officer. Now Rush is up to it too? It stings that after all this time they don't know him at all.

"I won't deny I'd be happy to find a good reason to end it all," he admits – first time he's put it out there himself. It sounds startling and cold in his own voice. "But I know my duty. I'm not offering this because I want it. I'm offering it because it makes sense that it should be me. Scott can do my job if he's forced to. TJ can do my job, if Scott refuses. No one can do yours but you."

He thinks Rush should look happier about this. It's a kind of victory for him, after all. The acknowledgement that in any hypothetical shared future Young would never have left him behind again, would have fought for him against Telford's machinations. The acknowledgement that Young knows Rush is more important than he is.

"After all the struggles, after Destiny tested and chose you, after we finally began to work together successfully, you think you'll be replaced just like that? You still think you're non-essential?"

Rush sounds insulted, as though Young's being stupid – which is nothing new – but the idea that Rush is reassuring him, praising him, that's something he really doesn't know how to deal with.

"Let me get this straight. You're volunteering to stay out because you don't want me to die?" He'd be touched if he could believe it. True, Rush has saved his life before. He's saved Rush's. That's just what you do out here. It incurs no debts, doesn't require thinking about. It's different if you form the intent and allow it to shape your plans. He strongly doubts that his survival features as a priority in any of Rush's schemes.

"Is that so hard to believe?"

Remember how you almost vaporised Scott and me in the shuttle? Remember how many times you tried to get rid of me? I'm the wrong man for the job, remember.

But if Rush can forget being abandoned on an alien earth alone, he guesses he can forget those other things too. "Well, maybe I don't want you to die. We're pretty even in that respect, so we gotta take other factors into account. Are you going to claim I'm more essential than you?"

Rush closes his mouth and angles his head away. It's a remarkably tactful response from him.

"So why are you volunteering?"

"I told you. I have the best chance of fixing it."

"You sure you can get it to work?"

Rush is still looking away, the fall of brown hair across his eyes glinting softly in the room's yellow spotlights. "Well I can't be entirely certain, can I? Not without knowing what's wrong in the first place."

And so they circle round again to the central fact that this is Rush apparently doing something very un-Rush-like. Why?

"What happens if you can't fix it?" The chair swims up out of Young's nightmares. He's never going to forget the way Rush deemed himself too important to sit in the chair, the way Rush circumvented Young's command so that he could persuade someone else to sit, the way he destroyed a good man's brain – one of his own people, no less – without a moment's regret or remorse.

Suppose Rush was left with the broken pod. Suppose he couldn't fix it. With time running out and the prospect of his own death before him, knowing that the ship needed him, that the crew needed him, what would he do?

The answer occurs to Young with horror and certainty, and perhaps a shiver of dark humour, because Rush is nothing if not consistent.

Rush would do what he had suggested when they had to find someone to shut the shuttle doors and asphyxiate in the process. He would draw up a list of the crew, select the least useful member, engineer a little malfunction to quietly put them down in their sleep. He would alter the records to show that there had been a fortuitous accident – for which, of course, he couldn't be blamed. Then he would take their pod.

It's an evil thing to think of anyone, but at this point it's not something he can put past Rush. And he can't risk that. He can't risk Rush's death. He can't risk the death of whatever innocent Rush might judge less fit than himself to survive. Nor can he put that kind of temptation in Rush's way. By living, Rush gave him the greatest gift he's ever received – stopped him from being a murderer. Maybe that's a debt he can repay after all.

"What would you do, Rush?"

Now the smile is back, warmth blooming in Rush's eyes. He's heard the sudden hardening of Young's tone and he... finds it amusing? Is happy because he has got what he came for? He surely didn't think he had to persuade Young to volunteer, did he? Was he worried the suicidal tendencies might have worn off? Thought Young needed a bit of prodding to decide to die?

"We'll have to hope we'll never find out, won't we?"

Young smiles in return. There's no point in being angry or appalled – it's just Rush. The guy is unbelievable, and perversely endearing with it. Like a difficult terrain for a battle – he can't change it by believing it ought to be different, he just has to take it as it is and adapt. Or Scott does, anyway. Not his problem any more.

"Yeah, and we never will. Because it's going to be me, and that's the end of the matter."

Rush doesn't argue. He half turns, as if heading out into the empty corridors, but then hesitates and turns back. His posture and expression has taken on some of the gentle dignity he wore so well when they believed they would be destroyed inside a star. "I should... but I wanted to..."

Young comes out from behind his desk, drawn by the other man's quiet. Free as he is, on the cusp of death, he can admit that even though Rush is a total shit at times, he has become precious to him, as everyone on board is precious, irreplaceable, wonderful because of their flaws and their virtues alike. He's proud to die for them all, even though some of them he'd gladly punch in the face.

With Rush it's just that little bit more intense.

"You want me to tell Eli?" He gets within a foot of Rush before the man looks up, frowning, like he's chewing over a puzzle in his head.

It earns him a rueful smile. "I think he would take it better from you."

"No kidding."

And when they're both on the same page like this, when they both come together to work things out, it's so fucking easy, it's so right, and it – oh, it makes him furious that they can't ever stay like this, can't ever stay in tune. And what the hell is he thinking now?

He turns to go, to find Eli, to put the strange moment of regret behind him, and Rush stops him with a hand on his arm.

"Wait. Not yet. I..."

Rush doesn't take the hand away. He steps forward instead, so they're close, closer than they've ever been without trying to hurt each other. Young's heart races in anticipation, and his whole body wakes up, recognising a threat. He doesn't know what to make of this, as the air heats and thins, and time slows, growing heavy and warm and dark around him.

"I wanted to do something before it's too late." Rush's voice trembles and his eyes are half afraid, half fiercely curious. "An experiment of sorts."

Cautiously, Rush's free hand lifts and touches his cheek. Four spots of heat and the palm like a burn. Young's still trying to figure this out because it's not... and Rush leans up, brushes his lips very gently over Young's. Warmth, fleeting pressure, the scrape of beard over his upper lip and his chin and he hasn't time to react before it's withdrawn.

He's looking down into Rush's eyes – less fear now, curiosity still, though the pupils are blown and dark with delight. The second time's a little deeper, the touch of Rush's tongue exploratory against the seam of his mouth. He presses back, still a little stunned, aware of everything slipping, realigning, as he falls towards realization. Then the seethe in his belly that he keeps for Rush, that compound that he thinks of as fear and anger mixed, catches fire and explodes.

Before he knows what he's doing he's got one hand tangled in Rush's long hair and he's kissing him savagely, slamming him up against the wall by the door. Rush grunts at the impact but his lying mouth is wide open, drinking Young in, and his long, clever hands are pulling at Young's shirt, untucking it, skimming inside, hot against his famished skin, nails scrabbling at his back as Rush tries to pull him even closer.

"Lock the door," he manages, as close to thought as he's going to get for now. The rest of it he's going to contemplate later or not at all. Because he's wanted this forever, he just didn't know.

Rush puts out a hand without looking, slams the door lock even as he's biting at the corner of Young's jaw, down the length of his throat. He's flush up against the bulkhead with all Young's weight pressed into him. He's not going anywhere, and for once he looks like he's enjoying it, a high flush on his cheeks and his eyes dazed and his cock hard against Young's belly.

Young reaches down to rub it through the age-soft material of Rush's jeans, and he makes a gorgeous noise, high pitched and breathy, tipping his head back against the wall and arching his spine to push forward for more.

Young takes the chance to pull off both of Rush's t-shirts and his own, and then there's skin and that's so much better, skin hot against his own as he crowds Rush's skinny, sinewy little body hard with his own. Still too many belts in this world, and belt buckles and trousers, and Rush is not helping, rutting into his hand with his eyes closed and his mouth open like he's wanted this forever too.

Young scrapes some coherence together for long enough to tackle the fastenings of their pants and shove them down. Thinks maybe this should be happening in bed, where they could take their time, savour it, but then Rush gets both hands on his arse and squeezes, hauling him in tighter and he's never... never done this with someone so strong before, someone capable of making him feel physically vulnerable. He had no idea it would be such a fucking turn on. And yeah, bed? Bed is far too much effort, when he can just wrap his hand around both of them and thrust against Rush's hollow stomach, slippery with pre-come and sweat.

Rush makes that noise again and lifts his legs to wrap them around Young's waist as they rock together. Young's growling deep in his chest, his mouth latched onto the join of Rush's neck and shoulder, and all his mind given over to the taste and the need and the regular swelling pleasure as Rush grits his teeth and struggles against him, lost in solipsistic bliss where he can't touch, though he's really, really going to try.

They come like anguish, one after another, and stand panting in each other's arms, hot, trembling and stunned. Young hides his face in Rush's neck, while Rush puts his feet down and uses his undershirt – still hanging disregarded from one wrist – to mop up the mess.

Young loosens his grip until it's no longer so desperately tight, gives enough to make it easier for Rush to breathe, but doesn't step away. It's nice – it's nice to have Rush plastered against him, quiet and sated and relaxed. There's a kind of peace to it that makes him wish...

Rush makes no effort to move away either, just circles one arm around Young's waist and pushes the fingers of the other hand into his hair, drawing nervous diagrams on his scalp.

"You must understand," Rush says at last, when they can't keep the thoughts, the words, at bay any longer. "This wasn't my idea – that you should die outside stasis. I want you to remember that I was opposed to this entire plan from the start."

Young lifts his head and kisses Rush gently on the corner of the mouth, touched, because this is Rush-speak for "I'm sorry," and even that kind of non-apology doesn't get dragged out of him easily.

"I know that," he leans down to pick up the guy's pants from the floor, help him get all tucked away and buttoned back up. "I don't blame you."

"It's just the best out of the available options."

Young laughs, because it's so like Rush, to come here and fuck him, to tell him that he wishes he didn't have to die, but he does, so suck it up. The guy... the guy is one of a kind, that's for sure.

"It's OK," he says, and is surprised to find how much it feels like a lie to finish off with, "It's what I want too."

Because, to be honest, right now the prospect of living doesn't seem too bad.