So, I've been thinking about writing a Purgatory fic for...since the finale, but I didn't want to just jump right into it. I've thought about it, and basically, this is my twisted idea of what happens. Sorry it's a short first chapter – I'm so close to finishing my novel that I can taste it, and that's what I want to be doing right now.

Dean hasn't felt this frightened in a long time.

Scared, yes. He's been scared. Scared of losing Sam, scared of dying, of letting everyone in the world get carved up in a slaughterhouse – yeah, that's the kind of stuff that'd scare anybody.

Being frightened however, is for kids. Fear is irrational, and dangerous. It's ok to be scared, that's just nerves, it's your brain talking to your body, telling you that you're about to do something fucking crazy, or you're walking into a trap. Being scared is having a brain that works.

Fear though, fear'll get you killed.

Especially in a forest full of monsters. Especially in a forest a million miles across, pitch dark, full of legions of monsters that have been gathering here since the dawn of time. Full of monsters that are already dead. Monsters he couldn't kill even if they could be killed, because he's got one knife and a gun with almost no bullets left, and splintered bit of useless bone.

Oh yeah, and his one hope has just flittered off, after telling him he was going to get torn to pieces.

So, Dean is fucking scared, but he can feel that edge of fear coming, the dangerous kind of fear that makes smart men dumb, and leads seasoned hunters right into the jaws of death.

A sharp, wet, crack cuts though the air, and makes his heart jump like a thousand volts of electricity. A screech follows that makes him look around wildly. He widens his eyes, trying to see in the dark, brings up a hand to cover his mouth and nose, cutting out the sound of his breathing so he can listen.

Another crack – the unmistakable sound of a violent, messy, dismembering. A piteous howl cuts through the air.

Scuffles, hard thuds of flesh against flesh.

Something makes an awful sound, somewhere between animal rage and human hate.

Crack number three silences it.

Dean waits in the silence, fear riding his every nerve. He's going to die. He knows it.

Castiel appears at his elbow, and Dean flinches away, almost jumping an inch in the air. He turns and glares at the angel, heart still hiccupping in his chest, only to see that Castiel is spattered in blood, and his hands are gloved in it.

"Cas?"

"That was...most unfortunate." Castiel says, looking down at his hands, and cleaning the blood away with a thought.

"You killed it?"

Castiel still looks shaken. "I did as best as I could. This is purgatory, and everything here is already as dead as it ever will be...but the creatures here can still be...damaged."

An angry, pitiable howl comes from the trees to their left.

"You mean..." Dean looks at the trees, "that thing's still alive? You just..."

Castiel looks sick, an expression Dean has never seen on his face. "made sure it couldn't get up again."

And with that, Dean is well and truly frightened.

(-* -)

Purgatory is vast, but empty. Unlike heaven and hell, there is no need for there to be anything in purgatory – no roads, or remembered houses and bars, no racks and pits – just miles and miles and miles of dark forest. A zoo for the most dangerous animals the world had ever known.

"Officially, that is, according to the Bible," Castiel says in a hushed voice as they sit at the base of a tree some miles from the creature Castiel had 'neutralized' planning their next move, "Purgatory is a waiting ground, somewhere souls come to be contained until they are placed either in heaven, or hell."

"I'm guessing that's not what happens?"

Castiel shakes his head, "No creature has ever entered heaven, or hell. God created heaven and earth, and purgatory was a place he made to contain Leviathan. Lucifer shaped hell, and so demons and damned souls go there, pure souls go to heaven...and, Eve's creations go to purgatory, because they belong nowhere else."

"So if I'd been stuck a vamp..."

"This is where you would have ended up."

"Great." Dean looks around them, unable to stop scanning the trees for danger, when danger is all that's around them. "and we can't kill them?"

"No," Castiel agrees, "they prey on each other, and though the damage they do is lasting, even unto disembowelment, decapitation, bisection..."

"Please stop," Dean says, "I get it, they get hurt, but they'll stay living, even if you cut 'em into slurry."

Castiel doesn't speak again, and Dean realises that's because he told him to 'stop' without giving him something else to talk about. He's trying to get used to Cas not being Cas anymore.

"Are we getting out of here any time soon?"

Castiel shrugs. "We might."

"OK, so how do we do that?"

"We don't do anything," Castiel tells him. "Purgatory is a prison – unlike heaven and hell it's doors only open from outside. We cannot get out, only an outsider can reach in and set us free."

"So what do we do?" Dean asks, angry, frustrated, and still incredibly afraid. "while we wait for God or Sam or Meg to bust us out?"

Castiel looks grimly out into the darkness, his face suddenly looking much older. "We survive."

And Dean is so far beyond scared that all he can feel is a frozen lump in his chest.

(-*-)

A couple of hours later (though it's difficult to judge with the forest still being dark, and his watch having given up the ghost when they jumped dimensions or however they'd gotten here) Dean asks a question. He hasn't been waiting to ask it, but it suddenly occurs to him, and the unpleasantness of it makes him say it aloud.

"Am I going to starve to death?"

Castiel turns to look at him, until now he's been glumly meditating on the tree line. "Quite possibly."

Dean thought about that for a while, leaning back against the tree and trying not to give in to panic.

He wasn't even aware that he'd fallen into an exhausted sleep until Castiel shook him awake. Dean opened his eyes and looked into the worried face of the angel.

"What?" he mumbled.

"Dean, you were asleep for over seventy-two hours." Castiel tells him, "I thought it best to wake you."

Dean shivers, he's suddenly extremely hungry, not surprising given that he's been asleep for three days.

"Why did I sleep so long?" he says, trying to get upright and finding that his legs are shaking.

Castiel takes his arm and pulls him into a sitting position, easily propping him up against the tree.

"There's no way to tell time here, your body must have been unable to keep track of how long you'd been unconscious."

"And nothing attacked us?"

Castiel looked grim, a shadow slicing across his face. "I've moved us thirty nine times."

Dean looked around at the trees, they looked identical to the ones that had surrounded them before. He shifts, and only then does he realise that he's covered in Castiel's coat. He's too tired to move it away, and he doesn't want to – what would be the point? It would only make things more strained between them.

"How'd you know I was out so long?"

"I counted."

"What?"

"Seconds." Castiel looks frustrated, "it was tiresome."

Unconsciously, Dean lets his eyes flutter shut again.

Castiel shakes him again.

"Hey," Dean whines,

"Stay awake." Castiel tells him.

Dean tries.

(-*-)

"I'm hungry," he says, about an hour later. It's really hard to gauge time, but it feels like a lengthy stretch has passed, so why not call it an hour?

"I don't have anything to feed you."

"So, are we just gonna sit here while I die?" Dean mutters, blinking his tired eyes.

Castiel thinks for a while. "No."

Dean's hunger gets steadily worse, and though he tries to sleep through it, Castiel keeps waking him up every six or seven 'hours' and telling him that he's slept long enough. The trees around them grow blurrier, and Dean can't focus on them, or his own thoughts anymore. He has no idea how long it's been since he last ate. He's also thirsty, and so bone tired he can barely think.

He wakes up from one particularly long sleep and the first thing he sees is Castiel's bloody wrist in front of his face.

"Drink," he orders.

Dean turns his face away with a gruff sound of dissent.

Castiel's other hand touches the side of his face, bringing him back to the sight of the blood crawling down over Castiel's pale hand.

"Dean, this is all I have for you – drink it."

And Dean does. God help him, he's too weak to put up much resistance. He leans forward, and, after a messy few seconds in which he can't quite find the wound under all the blood, he latches on, and sucks hard. The blood tastes like blood, and it's disgusting. Hot and bitter and not something he'd ever have put into his mouth by choice. But he swallows, and the ache in his stomach dissipates a fraction.

After a while Castiel draws his wrist away, and Dean wipes his mouth with the back of his hand, feeling sick and shaky, but a little less feeble. He's only just begun to notice the weird fluttering in his veins, the flaring and fading of energy under his skin, when he passes out.

Dean's dreams are fucking crazy.

He can hear light for starters. Which is new. It burns and deafens in one, but...somehow he can hear it talking, in a way he can't really understand. It pulses, intones with a deliberate voice. But when he tries to shout and tell it to stop, because it's hurting his head to listen, his own words come out in the same way – a kind of...frequency, like Hell's unturned radio. Scratching a crying and screeching.

There's more light in front of him than anywhere else, and it's shimmying back and forwards. It goes on forever, deep, but also tall – taller than Dean and taller than a telephone pole. As tall as a skyscraper.

And that, more than anything is what clues him in.

"Cas?" it's a thought, not a word, but the light grows brighter. There are little black holes in it, long tears that open into a starless night. No, not tears – just places where the light isn't. Like the light is skin, holding all that darkness in.

Dean's aware of himself now, he's a kind of seed sized spark. A ball of light, sort of like something he's seen before.

A soul.

That's it. Like the soul that Death had put back into Sam. He's just a soul. One soul.

It seems only natural, only inevitable, that he should move (because he can move now, and it's so easy. Easier than even breathing) into one of those long, black tears, a gateway into the light, into the darkness in it. He's just getting there, and the huge Cas-light is humming, a hum of tormented bees streaming from their hive, when a hand on his forehead jolts him awake.

For the second time in recent memory, he finds himself looking up into Castiel's face. The darkness of the forest is so deep after the searing light, that for a while, Dean had the afterimage of Castiel's true form burnt onto his retinas, a slowly fading bruise of light that pulses in front of his eyes.

Castiel's face is drawn and pale, and Dean notices with surprise that there's sweat on it.

"No, Dean." Castiel says, and Dean gets the sense that this was what all the humming was about. Castiel hadn't wanted him to get inside the light. Inside of him, Dean realises with a jolt. What the hell had he been doing? Trying to get inside of Cas?

"What the hell was that?" Dean rasps, moving away from Castiel clumsily, "and don't 'No, Dean' me, you put me somewhere like that, you can't blame me for freaking out."

"I didn't put you anywhere." Castiel says, and characteristically doesn't tell him exactly what it was that he had done. "When you next take my blood, just rest there, and resist the compulsion to..." he trails off.

Dean doesn't ask what it was he was actually doing, for some reason he now feels embarrassed about it. Whatever it was had clearly freaked Castiel out.

"Fine," he bites out, "but I hope Sam gets us out of here before I have to go vamp on you again. That was trippy as fuck."

Castiel doesn't disagree.