Post series two AU, so MAJOR SPOILERS for the series two finale. Whoniverse crossover, containing slight spoilers for the Aliens Of London and Christmas Invasion episodes of Doctor Who, and for the basic premise of Torchwood.

More Things Than Are Dreamt Of

Sam Tyler wakes from a dream of nineteen seventy three, a headache starting behind his eyes and the strains of Roxy Music's Ladytron still running through his head. He takes a couple of aspirin and sets his iPod to the Best Of Blur, buttons his shirt to the crashing chords of Song 2; nothing better to dislodge lingering mental tunes.

Annie was in his dream, and it was a good one, one of the ones where she isn't bleeding or screaming or dead. They were walking in a park, he thinks, or maybe a field; the music was playing somewhere and everything smelled like grass, and she turned to him and smiled and -

And he shakes his head and thinks of something else, things he has to do today, paperwork that needs completing and the fact that he's running low on olive oil. The dreams come nearly every night, dreams of Annie and Gene and the rest of them, of his dingy flat and the Railway Arms, Nelson behind the bar. Sometimes he wakes with a smile on his lips, sometimes his cheeks are streaked wet; sometimes he sits up screaming, the feel of blood still hot on his face. The dreams come, he accepts that, but there's no point obsessing over them, because they're not real.

Sam knows reality, knows the difference between fact and fiction. He has always believed that the truth is more important than anything, and he can't lie to himself, not even for a chance to be happy.

Sam Tyler didn't jump. He's not sure if that makes him cowardly or courageous, a fool or a fighter, but he got up on a roof to throw himself off, send himself back, and he didn't. Every day he questions this decision, and every day he continues living, feeling like a stranger in his own life, feeling like he's watching the world from behind glass, but living nonetheless.

This is reality, and he's still alive.

---

Another murder called in, and it's the same as the others, identical, brutal MO. The fourth such killing in the past two weeks, people unconnected by background, race or locale. The only thing they have in common is that they were outside at night: a beggar sleeping rough, a girl on her way from work, a man who left the pub and never made it home. Throats opened and bodies savagely lacerated. What look like bite marks and scratches, and they pulled in a dental forensics expert for that, thinking it might be an animal attack.

"The teeth are too flat for a predator," she told Sam. "Too blunt. If it's an animal, it's something with teeth like a human's - an ape. Or it might be a human wearing some sort of dental prosthesis."

"Or?" Sam asked her.

"Or," she replied, "It might be something else entirely."

They have no suspects, no motive, no leads. The only thing they have are four dead bodies and a fistful of questions, and they have to stop this now. Sam heads for the latest crime scene, a narrow laneway that's a common shortcut for locals. When he arrives there's a trio of people in civilian clothing clustered around the body, forensics and uniformed officers standing at bay, shuffling uncertainly. Sam has no such insecurities. He strides up to them, pulling his badge, and grabs the tallest man by the arm, tugging him around.

"Excuse me," he says as politely as he can manage, "What do you think you're doing?"

The man flashes him a megawatt grin, casually steps between Sam and the scene, but he can just about see the woman - tall, dark, elegant - passing some sort of device over the body; a camera, maybe? The man sweeps an arm around Sam's shoulders and turns them both so they're facing away.

"I'm sorry," he says (American; bloody typical), "I didn't catch your name."

"DCI Tyler," Sam tells him pointedly. "Officer in charge of this investigation. Who the hell are you?"

"Captain Jack Harkness, Torchwood." And oh yeah, Sam's heard of Torchwood, vaguely, some sort of special branch with an unspecified brief; spoken about in whispers and rumours, and if you hear of them turning up at an investigation, you know it's something out of the ordinary. But captain, that's a military title, and Sam wonders just where this American and his secretive organisation fit into the grand scheme of criminal investigation. Right now, though, he just wants to know what exactly they think they're doing.

"Well, Captain, do you mind if I ask what Torchwood are doing at my crime scene? Nobody should have gone near the body until forensics was through with it."

"Oh, right," Harkness says easily, "Well, it's our crime scene now - and our investigation, actually. So no need to worry about it."

"What?"

"Yeah, special circumstance, requires delicate handling, sort of thing we're equipped to deal with. Not that you haven't been doing a great job, I'm sure," he pats Sam reassuringly on the back. Sam shrugs his hand off irritably, scowls at him and cranes his neck to take another look at the scene; the woman's finished whatever she was doing and now the other man, a thin-lipped, narrow-faced bloke, is prodding at the body with a set of forceps.

"I've heard nothing about any special circumstances," he says, "And until I do, this is still my investigation, and I want your people away from there so forensics can do their bloody job!"He knows he's almost shouting, but he can't help himself, this is completely ridiculous. Harkness just grins again, infuriatingly pleasant.

"Call your superintendent," he tells Sam, pushing him gently but firmly away. "He'll explain everything."

Sam has the distinct feeling he's just been dismissed, but he's not going to lie down so easily; he turns back, only to find an impenetrable wall of broad, coat-clad back between him and the body. Obviously Harkness considers the matter to be closed and Torchwood to be in charge. Well, they'll see about that.

Sam rings the superintendent, who explains everything; and just like that, the investigation falls out of his hands.

---

The problem is, nothing seems quite real to Sam, nothing has since he came back. It's only the weight of experience that tells him this is what actually exists, thirty seven years of this life compared to a few months of the other, and it is only this conviction that keeps him clinging. Reality is this grey place, this life that was once his, and oh, Sam can see now, he was slipping away long before his accident; he's been losing himself for a long time. He just never realised it until he found himself, in a place that wasn't real.

Recently, though, even the reality he knows seems to be less than certain, fracturing and sliding away like an ice floe in spring. True, there are no girls in red dresses crawling out of his television here, no family addressing him over the radio, no sounds of his own failing heartbeat echoing in his ears. But things are strange. Just last Christmas he sat with his mum and watched amateur footage of a UFO over London, the turkey forgotten and burning in the oven; a hoax, it was said afterwards, but people saw it, too many of them for denial. He's heard about what crashed into the Thames too, though he was comatose at the time: a military aircraft, supposedly, but the rumours are everywhere. And really, aliens? Is that any less fantastic than time travel?

And now right under his nose, these weird murders and Torchwood's intervention, this organisation that doesn't seem to exist, no matter where Sam looks; a group of ghosts.

This is the reality he knows, but beyond that, Sam's not sure of much anymore.

---

It's four in the morning when he wakes, gasping, soaked in sweat. His dream was an unpleasant thing, all blood and accusations and the cold, dead eyes of people who trusted him; hard experience has taught him that he won't sleep again tonight.

The sun is just beginning to rise when Sam takes to the street, shivering a little in the cool air until his muscles begin to stretch and warm. He finds his stride easily, falls into the familiar loping pace at which he always runs, feet striking the pavement rhythmically. Running is good, gives him space to breathe, and he doesn't ever think while he's doing it, just concentrates on his pounding feet, his steadily thumping heart, the efficient in/out of his lungs. And if he runs well enough, far enough, he can outpace all his fears and regrets and the terrible gaping emptiness that sits in his chest after dreams like that; not forever, just for a little while, but any reprieve is welcome.

He usually listens to music, but this morning he relishes the quiet, and it's because of this that he hears the scream. Turns towards it instantly, copper's instinct kicking in despite the fact that he's unarmed and doesn't even have a phone to call for backup; someone's in trouble, and the Guv would kick his head in if he didn't go to help. He turns down an alleyway and what he sees is this: a man on the ground, flailing and shrieking, blood spattering, and crouched over him, something, snarling and clawing at its victim, dark leathery skin and a domed head, lips twitching back from big, blunt teeth. It is, he can't help but notice in that split second, wearing a blue plastic jumpsuit.

"Hey!" he shouts, stupidly, but it does the trick, the creature turns towards him and only then does Sam wonder why he thought it would be a good idea to attract its attention. The man is moving more weakly now, screams dying to gurgling as he drowns in his own blood; Sam backs slowly away, trying to keep his eyes on the creature while simultaneously looking around for any kind of weapon. He manages to yank a loose brick from someone's garden wall, hefts it and considers running, but his legs are already burning and he knows he won't outpace it. Better to face this thing head-on rather than be snatched from behind, he tells himself, and the thought is barely out before the creature charges at him, arms spread wide and teeth bared.

Adrenaline floods through Sam's veins and he raises his brick to swipe at the thing's head, while in the same instant thinking that dying won't be so bad, and he can hope, can't he? Hope that maybe he'll be back where he belongs? Oh please, please...

"Come on, then!" he screams, swings his arm, and somehow, miraculously, the blow connects. The thing yelps with pain, stumbles back, then rights itself (dark, dark blood dripping from a gash in its face) and hisses at Sam with a sort of resentful stupidity. He raises the brick again, panting and exhilarated, knowing his chances and not caring, and suddenly all the shit in the world drops away, and Sam feels completely, wonderfully alive. He realises he's laughing, wild and hysterical, and he can't stop, doesn't want to stop, and the creature yowls and lunges.

And then there's the sound of running feet and he hears the sharp crackle of stun guns as the creature is dragged off him, howling and writhing and finally dropping to the ground. Sam looks up, his blood-stained brick still clutched in one hand, and sees Captain Jack Harkness looking down at him, wearing a bemused expression.

"DCI Tyler," he says, quirking an eyebrow. "Didn't expect to see you here."

"Oh I turn up in all sorts of places," Sam tells him, and starts laughing again.

---

The funny thing is, Sam thinks, that he spent so long believing reality was some immutable thing. There was truth, and there was fiction, and Sam thought he knew which was which. Nineteen seventy three nearly destroyed Sam's ideas of "real" and "not real", turned them upside down and inside out, yet at the end of it all he still made that choice between fact and fantasy. And even when that choice made him unhappy, made him feel like a dead man in a live man's body, he still clung to his ideals of reality. Because what's real is real, and what's not is not, and that's all there is to it.

The funny thing is, it turns out reality is nothing like he thought it was, is so much grander and more terrifying and incredible than he has ever, ever imagined. Worlds beyond worlds beyond worlds, and all of them full of life, and only a handful of people on this entire planet know.

The funny thing is, he's not sure if he wants to know more, to know everything, or forget it all completely. He's not sure he'll have a choice.

---

"So you hunt aliens," he says. Captain Harkness nods, a wry smile stretching his mouth.

"That's right. If it's alien, it's ours."

"And that thing earlier was..."

"We call them weevils. Technically Manchester's out of our jurisdiction, and Torchwood One - that's London - would normally deal with it. But since it's sort of our fault it ended up here in the first place - long story, involves several misunderstandings and a freight lorry - I decided we should take care of it ourselves."

"It killed people," Sam reminds him. "Five people. And you decided to exclude the police force from your investigation."

"What could we tell you - that we were chasing a vicious creature from another world? People have died who shouldn't have, and I'm sorry for that, but if this sort of thing went public it would cause panic."

They're sitting in Sam's flat, drinking coffee, and so far he's heard half a dozen unbelievable things. The reason they're here is because Harkness invited himself over while his suboordinates are, in his words, "clearing up"; Sam doesn't particularly want to know what that entails. He feels numb after his exhilaration of earlier; he thinks maybe he might be in shock. Harkness keeps grinning at him.

"If you don't want this getting out," asks Sam, suddenly wary, "Then why are you telling me?"

"Because you deserve an explanation for what just happened," says Harkness. "And because you're not going to remember it in a few hours." He takes a small pill bottle out of his coat pocket, and shakes a single white tablet onto the table between them.

"It's easier if you take it willingly," he says, his voice somewhere between sympathetic and determined. Sam looks at the pill; it's very small.

"And that'll make me forget?"

"Yeah."

Sam tilts his head to look Harkness hard in the eye, his mouth curling in a way that might be bitterness or amusement; he's finding it hard to decide right now. Then he asks, because he has to.

"How much can you make me forget?"

Harkness looks taken aback and Sam feels a small surge of triumph; this is the first time he's seen the man ruffled at all. The uncertainty is gone almost immediately, though, covered by that smooth, relaxed façade.

"How much do you want to forget?" he asks, and Sam tells him. About the accident, the coma, the entire bloody world he created inside his own head, and how he was happy there, happier than he's been in a long time. How he can't make himself go back, out of cowardice or rationality or guilt. How he thinks it might be better if he forgot it all, and then maybe he might be happy here, in this real life of his, or at least content. At least unaware of his own unhappiness. He pours all this out, and Harkness sits there and listens without saying a word, his face unreadable.

"You think I'm crazy now, don't you?" Sam finishes. Harkness just looks at him for a long moment, then shakes his head.

"I've travelled in time," he says. "And I've died. I've seen things you couldn't imagine - things I hardly believe myself. Crazy is relative."

"I don't know what's real anymore, " says Sam. He can feel tears stinging at his eyes and he knows it's the shock, the after-effects of the adrenaline, and he blinks them back angrily. Harkness is still watching him.

"Reality isn't such an easy thing to define," he says. "I mean, look at you - before today, your reality didn't involve aliens coming through an interdimensional rift in the centre of Cardiff, did it?"

"I suppose not," Sam acknowledges. "So what are you saying - you think it was real? You think I should try to get back?" The numbness is melting away now, panic bleeding in at the edges and he feels almost frantic, desperate and drained, and god, he needs someone, anyone, to tell him what to do. What should he do? He stares appealingly at Harkness, who lets out a long, slow breath that's very nearly a sigh.

"I think," he says carefully, "That life is too important to throw away. It's beautiful, and it's horrible, and in the end it's all we have. If they're waiting for you, well, then they'll wait for you. But you're here now, you're alive, and you have to make that count." He pauses, and a slow smile spreads across his face. Sam doesn't think he trusts that smile.

"Tell me, DCI Tyler, how would you like to come and work for me?"

"What? Work for Torchwood?"

"Sure, we could use another good man on the team. You've taken the whole "aliens are all around us" revelation in your stride, and you can handle a weevil pretty well - though I'd use a stun gun next time, instead of the brick. Job satisfaction isn't guaranteed, but it won't be boring, I can promise you that."

Sam can't talk, can't think, can only stare at him, and after a few moments Harkness looks concerned, waves a conciliatory hand.

"No problem if you don't want to, obviously, I can just retcon you. I mean, it would involve moving to Cardiff..."

"I could do that," Sam says, or at least he hears his voice speaking, though he can't remember making any sort of decision. Harkness beams.

"Great!" he says. "We'll sort the move, then, and get all your stuff sent down. Are there people you need to tell you're being transferred?"

"Just my mum," says Sam, because really, there isn't anyone else; there would have been once, but not now, and that makes this choice all the easier. Maybe this is the coward's way out again, clinging onto a life that no longer means anything, but he's just had his first glimpse of a universe that's spectacularly big, and unbelievably alive, and Sam thinks he'd be a fool not to stay and look some more.

"Well then," Harkness gets to his feet and extends a hand, grinning. "Welcome to Torchwood, DCI Tyler."

Sam grips his hand, shakes it firmly, and feels himself smile in return.

"Call me Sam."