Castiel stays with Dean for a long time, long enough for the sun to come up and disappear again. His skin is frozen by the chill air; he's soaked in cold, clotted blood, Dean's body lying mostly in his lap. He cries without conscious effort, feeling the tears run down his face and drip from his chin on to Dean's bloodied chest.

They killed him. Men had taken them both, caged them, and now that they had found something, anything close to completeness...they had killed him.

Castiel is an angel, he isn't used to using the language of desire, of hate or passion of any kind. He can't name the feelings that pour over him in all the hours he sits by the corpse that once housed his lover. He wants Dean with a kind of mad intensity, wants to see him move and speak and hunt. He wants to have the man and woman who killed him alive again, so that he can hurt them in the ways he is hurting, the ways he doesn't understand.

That's the crux of it, he doesn't understand, any of it.

After his long vigil he buries Dean's body, and those of his murderers, he can't risk them being discovered. Before confining him to the frigid earth he removes the necklace that was always around the neck of the other man, presumably the property of his host. He keeps it anyway.

In their hollow he exists without much food, without even sleep. He can't function like this, when it feels like most of him is somewhere else, dying. He eats the various plants that grow around the woods, he sleeps in Dean's place, smelling him on the blankets and furs, sickened by his own weakness, the sentimentality which is not part of his race.

Dean has introduced him to hunting, to humanity and violence, vicious pleasure and sex.

And now he's gone and Castiel is left with desires that trouble him, and a kind of...wound, in him. One which he cannot ease and which cannot heal.

It's weeks before he comes to realise something which really should have occurred to him sooner.

A knife wound couldn't kill a demon.

Dean's host was dead, but the demon himself would perhaps have been returned to Hell.

The hope that flares in him is more painful even than his grief, because he is powerless to descend into Hell and Dean, if he is alive in some form down in the pit, is powerless to return.

If he even wants to.

The traitorous thought cuts him and he tries to avoid it. But it's true, his brothers, his Father, they abandoned him even though they were supposed to love him. Dean is a demon, what can he know of love and loyalty?

And yet he promised to kill whoever stood between them, as Castiel himself had slain his Father's children.

He finds himself looking at the frost rimed ground, even though he knows Hell does not exist beneath the earth. He wakes to imagined screams in the night. He dreams of Dean and blood and hell fire, and he wonders what it would be like to die, to end the confusion that he feels.

Though of course he is unable to obtain even that relief.

Dean dies in the arms of an angel, and wakes at his brother's feet.

Around them hell stretches in either direction, eternal and dark. Above is the same as the pit below, writhing bodies in the earthen walls, over the ledges and dripping blood over the sulphur formations.

"Welcome home." Sam says, laying a hand on his hair. Sam's hand, like everything else, is covered in blood and sweat and the thick oils that let the racks run smooth. "I was beginning to think you were lost to us."

"Never." Dean sits up, noticing the stink of the place for the first time. Sulphur and blood and vomit, fear and pain and animal, feral smells of hate and malice. There's the faint odour of burning feathers, something he had once associated with Lucifer.

Castiel. His heart twists as if a hand has closed around it. He needs Castiel.

"Brother?" Sam looks him in the eye, yellow iris's beaming to the core of him. "What happened on the surface?" He crowds close to Dean and inhales deeply. Even with his host body cast off and his demonic form resumed, the odour of Castiel's grace is embedded in him. "Oh Dean." He murmurs sadly, "What has happened to you?"

"Sam..." he folds in on himself, crouching to the filthy ground.

"You've been with an angel...you've..." Sam's eyes are like the fires around them, bright and unquenchable. "You're in love." And it's like the worst curse that has ever been uttered, in Heaven or Hell.

The other demons, crawling over their assignments, the twisting souls which have neither eyelids to block out the horror nor hope of rescue. Dean shudders, knowing that Sam in this moment is fully the King of Hell, and will consign him to a rack for eternity for his folly.

But the yellow eyes dim, fading to brown as the demons resume their work.

"You love it more than me." A statement, not a question.

"I could not reach you." Dean answers, hoping that it pleases his brother.

"And now you can't return to him." Sam counters placidly.

If there was water in hell, Dean would cry for the angel that he had lost.

"I will try...I can wait." He says instead, looking up into the brown eyes of his brother.

"You will have to." Sam shakes his head sadly. "And you cannot stay here, not within the final circle of Hell...you're contaminated, Dean."

Dean knows that Castiel's grace still clings to him. He has been wrapped in an angel's wings, he's been inside his vessel, known him in all ways open to him.

He cannot truly be something of Hell now.

"I'll find somewhere." Dean gathers himself, prepared to wander every circle of Hell for as long as it takes to find a way home. Wherever Castiel is, that is where he wants to be.

"I will miss you." Sam looks at him, long and hard. They have been brothers since their lives were lighter, carried out on earth amongst other men. They have been together for centuries in the pit of Hell, and now they will separate, possibly for the rest of eternity.

"And I you." Dean leaves the centre of Hell, unable to imagine a farewell equal to the lifetimes he has shared with Sam.

He turns to walking through the demons who snarl and turn from him and his corrupted holds only to Castiel, thinking of him, so far away, as he travels through the bowels of Hell.