Jack toys with the idea of leaving the flat in darkness, as he closes the door behind them. He isn't sure he wants to look at that face again. There's a nagging urge like a scalding heat inside his head to take the man from behind, strip him in the dark, and fuck him with his eyes closed. That way, no one gets hurt. He doesn't have to look into that strange face knowing how familiar a mind lies behind it, and he doesn't have to acknowledge the memory, the persistent, irrepressible, half-imagined memory of a spark of recognition behind hard blue eyes in a hospital in 1940s England.

He wants the safety and the calm and the comfort of the darkness, but he flicks the lights on anyway. He can't let this seem weird to his lover. It's just an impulsive fumble with a random stranger, and come the morning they'll be nothing but the latest in each other's long list of similar encounters. He puts the lights on, and stashes his keys in an ashtray. He takes off his shoes and hangs up his coat, glances at his reflection in the mirror. Some days he's amazed he even has one. He battles monsters and demons every day, but the thing that startles him most is seeing his own face looking back at him from the flipside of a pane of glass, staring back across unknowable distances, looking him straight in the eye.

"I wouldn't be too concerned with your appearance," says the man with the wispy blond hair. "I'm here, aren't I?"

Jack tilts his head. His reflection tilts too. Behind him, his flat is cast in whites and greys. There's nothing homely about it, but it's familiar and it's his. Weird, he thinks, how a universe that contains Daleks and fairies and psycho murderers around every corner can throw up something so quaint as a device to show you what can already be seen.

"Jack?"

He spins round, all nerves, his usual suave exterior forgotten and discarded. The man raises his eyebrows.

"That's what your name is, isn't it?"

"I told you that."

"You did. In the shop. Jack Harkness."

"You didn't tell me yours."

The man laughs lightly. "Oh, names aren't important, Jack. Not for our purposes."

Our purposes, thinks Jack. And what are those, exactly? I used to know what mine was. I was going to find you and scream in your face. Beat the shit out of you, maybe. Some version of you I'll never know. I didn't intend to kiss you, not in the middle of a coffee shop in 1960s Cardiff, or anywhere else. Didn't mean to bring you here, can't exactly tell you that now…

He watches the man move around the bare flat, examining the framed print on the wall, smiling at the single photo Jack possesses. His team, all eight of them, most of them smiling, him crouching low in front of them. Smart kids. He'll miss them, when they're gone.

What is your purpose, Doctor? What are you doing here?

Jack hears himself say, "are you sure you want to…?"

"I wouldn't have come if I wasn't," says the man. "Why, are you having second thoughts?" Something sparkles in his eyes. "New to this, are you?"

"No. And no." Actually, he's having third thoughts. This is a bad idea. It's a bad, stupid idea. So many reasons why he should walk out, now. So many reasons why he won't.

"Traditionally, the opening line is 'would you like a drink?'," says the man, perching on the edge of Jack's desk. "And the answer is yes please, whatever you've got and however it comes."

Jack nods mutely. He goes into the kitchen and opens the cupboards. He hasn't eaten in about a month. He never feels hungry, and he can't starve to death. He's already tried. In the cupboards are a packet of mouldy Jacob's crackers, a tin of beans (use by 1956), and some cough syrup. He has some milk, though, and it is ice cold beneath the sink. He pours a mug, hands it to the man without an apology for the lack of anything stronger, and drinks from the bottle. A long, deep drink. He tries not to think about what he is doing.

The man seems glad for the milk, and finishes his mug. Jack takes longer to finish the bottle. They drink in silence, Jack crumpling the foil bottle top in his fingers. Nervous. No. Terrified. The man – the Doctor – looks like a phantom under the single bare bulb. He's too pale, too young, too fragile. A literal shadow of himself. But that isn't right either. For all his physical presence, the Doctor Jack knew was soft as a kitten on the inside. This one is hard as ice beneath the surface. He can tell with a single glance at those eyes, all innocence and purity until he lets you look deeper.

Jack thinks, maybe, this Doctor would be able to take a blow to the jaw. Just one. A right hook. It would bring Jack more relief than rain in the desert.

He stares at the wall, deep in thought. The man moves from the desk, takes the cup through to the kitchen, and runs the tap. Jack listens to the washing-up sounds. He doesn't want to meet the man's eyes when he returns, but he does it anyway.

"Then," says the man, "you might ask if I'd like to sit down. Or you might," he adds, "be as tired of waiting as I am."

Jack takes a step backwards. The man follows him, maintaining his distance but not allowing it to increase. He walks back until his legs are against his bed, and he stops. The man follows. Jack hooks his thumbs under his braces and eases them off his shoulders. He is breathing quickly, too quickly, the anticipation ganging up with the fear and the rage, and threatening to tear him apart. He fumbles with his shirt buttons, fingers like soft spaghetti, his eyes fixed on the man he is finally starting to think of as the Doctor, watching him pull his jumper over his head and start on his own shirt. The Doctor's fingers are nimble, and he is shirtless long before Jack. He doesn't offer to help, simply waits.

Jack doesn't know how he manages it, but he strips to the waist. He's been dead drunk before and experienced fewer clothing related complications. He peels his shirt from his arms, realises it is soaked in sweat. Flings the garment away from him. His hands move to his trousers, and the Doctor mimics him, but Jack can't make the button or the zip do what he wants. Soft, almost paternal, hands are there to help him out. They take hold of Jack's hands, and lower them to his sides, and just when Jack thinks the man is about to undo his fly, he stops, and catches Jack's eye.

"Relax," he murmurs. Gentle and close and welcoming. Jack is torn by the twin urges to shove him away, and take him in his arms. He wants the comfort and reassurance and safety that comes with the Doctor, and he wants revenge for the loss of it. He stands, trembling, as the stranger examines his features.

"Breathe slowly, Jack. Calmly. Do as I say."

And he does. He calms his breathing, and does exactly as the Doctor says. Never doubted him, he thinks, but that was always a lie.

He breathes slow and shallow, and he feels the world start to fall away from him. Doesn't matter. There are plenty of other worlds. The Doctor lets go of his hands, and touches his face, and Jack sighs at the wonderfully cool touch. He doesn't want to move from here, or for time to drag them on, he simply wants to stand in this room, with all these possibilities, and the Doctor gazing at him with that infinitely compassionate expression. This is what he always wanted. Not the adventures or the sex, just the simple affirmation of being held, the reassurance that he didn't have to try, simply had to be

The moment stretches out, and then twangs back as the Doctor lowers his hands to his sides. Jack reaches out for him, but whatever existed of lust and rage is gone, taken from him by the Doctor's touch, and –

Oh god. It's gone.

Jack wraps his arms around his bare chest and sinks his teeth hard into his lip. The anger slipping away from him felt good, but there is nothing there to replace it. Not yet. Just an empty nothingness that he's falling into. No despair, no fear, no horror. No hope. Just nothing. The need for catharsis is gone. His eyes sting, and his brain is trying to burst from his skull, and his knees ache, and wants to tear at his hair and scream at the darkness…

He stumbles, and the Doctor catches him, and helps him on to the bed.

"Jack," he whispers. "Jack, I'm a Time Lord. The clue is in the name."

"Oh god. You know me."

"Did you ever really think I wouldn't?"

He wants to claim that he didn't, that he knew all along the Doctor recognised him, that it was part of the whole plan to make the Doctor pay for abandoning him, but he can't start lying to this man again. This isn't supposed to happen. The only two scenarios Jack had let himself imagine were sex and violence. It had never occurred to him the Doctor would simply fix him without a word. He certainly never though the Doctor would break him with a touch.

He feels the soft nudge of a mind moving against his own. The Doctor is holding his hands again, looking deeply into Jack's eyes, staring through him into the future. Jack wants to fall into that mind and be consumed by it. If the Doctor can take away his hate and his fury, why can't he take everything else, and leave Jack a hollow husk, lifeless at last?

I can't do that, whispers a voice in his head that isn't his. You have to go on, Jack. As do I. Try not to think of it as a curse, more of an experiment in eternity.

The Doctor touches Jack's chest, and he shies away, but those confident alien hands remain steady, and suddenly Jack is allowing the Doctor to ease him on to his back. Jack thinks of his bed back on the TARDIS, of different hands pushing him down, different lips seeking his.

He rests his hands on the Doctor's hips, frightened by how different he feels, and tries to remember how to want someone. The Doctor is half-on top of him, looking down, but there is nothing predatory in his eyes, nothing lustful or indecent. Nothing but compassion and a suggestion of concern. His position isn't sexual, it's protective. He touches Jack's hair like a mother. Something unfamiliar, a quaint sensation not unlike falling, laps at the edges of Jack's mind.

"I haven't slept," he says, "in more than a decade. I want to. I just can't."

"You will," says the Doctor. "Eventually."

He kisses Jack on the forehead, hesitates, then kisses him on the mouth. Jack hears his own sigh of relief, loud in the still night. He knows this sensation now. It is peace.

"Thank you," he says.

The Doctor shakes his head. "I've done nothing, Jack. I can't fix what my future self has done. I can only offer sanctuary, for a time."

"Let me come with you."

"You're needed here."

"Then stay with me."

He smiles. "I can't. But there are others, and, in time, you may meet them."

Jack shakes his head. "What are the chances of finding your other selves in twenty-first century Cardiff?"

"You sought me out, but I knew where to wait," says the blond man.

"How?"

He laughs, softly, and lies back on the bed, resting his head on his hands. "You wouldn't understand. Unless you have a degree in Time Lord neurology you've never mentioned."

Jack closes his eyes and pushes his fingers between the Doctor's, letting their hands lie between them on the bed.

"You know what's going to happen?" he says.

"I know some of what might."

"Why wait for someone who might not have come?"

The Doctor doesn't answer at once. He squeezes Jack's hand, ever so slightly, as though afraid to ever let go. Jack keeps his eyes shut, concentrates on listening to his breathing, and the Doctor's; his own heart thumping, and the faint double-pulse from the body beside him. He thinks about Torchwood, and Cardiff, and the Earth. The Doctor is right, they need him. They need him, perhaps, more than he needs the Doctor. But Jack isn't entirely comfortable with being one of the good guys. He could stow away in the TARDIS, persuade the Doctor to let him stay, or take him somewhere else, somewhere he's never likely to see another Time Lord so long as he lives.

Part of him wants that, desperately.

"I couldn't risk missing you," says the Doctor. "I knew you were important, and I knew… that you needed a sign. I couldn't keep this from you, or from myself."

"Will the others feel the same?"

"Some of them will, perhaps."

That is enough for Jack, for now. He releases the Doctor's hand, feels the creak of the bed as he sits up. He doesn't want to watch the Doctor leave.

Suddenly he is being kissed, not gently or compassionately, but with an intensity that startles him. He resists the urge to grab the Doctor and pull him close, but he returns the kiss with fervour. He doesn't protest when the Doctor pulls away just as suddenly, but his breath has quickened, his heart throbbing in his chest like a gaping wound.

Jack lies in he dark, the unfamiliar taste of the Doctor still fresh on his lips, his eyes tight shut. He can't see this happening to him again.

There is the rustle of clothes, the sounds of movement, footsteps on the bare wooden floor. There is the clunk of the door opening, and the footsteps hesitate.

"Goodbye, Jack Harkness," says the man who will become the Doctor – his Doctor. "I look forward to meeting you."

And then the door closes, and there is no more to hear.