A whole episode about Dean's guilt? GREAT! This is what the series needs, some balance, some exploration of Dean as a character in the now.

Jo's in it? AWESOME! Her death was like a blade to him! (yay! Melodrama!)

Sam's a witness? Ok...I guess that makes sense, kind of overplayed, but it's a key part of the show...

OOOH a third witness? Guess that's Amy...oh well, maybe now the trial's over they'll mention...

Oh. Credits.

Where the fuck was Cas?

Dean drops the poker to the floor, still looking at the spot where Jo's ghost had been seconds before. The floor is scattered with the remains of his salt circle, and he's too concerned with the devastated look on Jo's face to worry that she'll rematerialise behind him and finish Osiris' dirty work.

He's panicking, and that in itself is bad, because he thought he'd passed the panicking stage the third or fourth time his Dad had taken him out hunting. Fear was ok, fear was useful, but panic made you sloppy, made you make mistakes that cost you your life.

The last time he'd felt this helpless, this wrong, Sam had been dead in his arms.

Panic rises to clawing terror as the walls of the room start to flake away, paint and plaster, brick and siding, spiralling away and...

And down.

Hell yawns around him, breaking through the walls and tearing chunks from the floor. There's a sound like live meat and metal torn together in a blender. Electric storm clouds, white hot chains and blood, blood running over everything, fresh arterial red on caked on black, running like candle wax. Hot and cold.

Dean's whole body is screaming at him to run, but there's nowhere. There was never anywhere to run. Isn't that what Hell was all about? Being trapped, being locked in forever with what the worst things in the world had spent eternity thinking up?

And it's not just seeing it. Dean's seen Hell in his nightmares countless times, but now he can smell it, the blood, not just a room soaked with it, not just a rotting abattoir, but a dimension, and entire universe of blood. Burning skin and hair and insides, and a taste that crawls into his mouth, like the hole where a tooth has just been torn out – raw and metallic, festering nerves.

The cyclone of Hell roars around him, a hoard of unseen thing watching, waiting with hooks in their hands and razors for fangs. Hell wants him, has been screaming for him like an animal for its young. He belongs in Hell. He was born in Hell. After forty years in the pit he had even come to believe it.

There's a real fire in the pit, but it gives no light, only heat.

"Hello Dean."

Dean only realises that he's shaking when the hand comes down on his shoulder.

He can't talk, can't form words with this terror in his very veins.

"Osiris sent me." Castiel sounds like he always did, immovable, certain. "This is your sentence."

"You're the last witness." Forcing the words out makes the fear spike, because he must be still, he must be silent, or Hell will find him. Hell will drag him down. Speaking dislodges the hot glaze of tears on his eyes, true fear filling him like madness.

"Yes." From the corner of his eye, Dean can see the pale blur of Castiel's face. "You refused me." Castiel says, voice low as if he too is afraid that Hell will notice them. "You wouldn't even see me."

"I thought..." Dean chokes on it.

"You killed me." Castiel practically whispers. "I came for you, here...and you killed me, over...and over again...every times I saved you...tried to...and each time I died, you never said a word."

Raphael.

Stull Cemetary.

And the false realities; Chitaqua...Vancouver.

Leviathan...

All Castiel. All Dead because of him.

"Heaven tortured me." Castiel breathes. "Tortured me...for so long that I couldn't think...could barely understand it...and you turned on me."

Dean blinks and he can swear he hears the tear evaporate as Hell churns and reaches for him.

"I saved you, from Hell." Castiel's voice grows unsteady, and the idea that he might be breaking, crying, is gut wrenching. "And you made me suffer...cast me aside...let me die...and even now you deny me fair witness..."

The bravest thing Dean has ever done, will ever do – is turn around.

Castiel's skin is almost painfully white, blood all over him from the final grapple with Purgatory. Behind him, Hell leers impatiently, hungry for the return of Dean Winchester's soul. The finest meat it could hope to feast on.

If Castiel's eyes were piercing before, now they are eviscerating.

"How could you forget me?"

Hell screams, and the sound cuts into Dean like a blade. It's blinding, all consuming terror, and he can do nothing escape it.

The next thing he's aware of is the feel of cotton against his skin. He's not sure when he pitched himself at Castiel, or how he came to have his arms around him.

He just knows that he isn't letting go.

The apparition flickers, but Dean is not thrown into the pit. Castiel remains still, silent, allowing himself to be held.

Hell fractures into non-existence. The walls come back up, stark and silent, the floor is once more solid. Hell only a memory.

Castiel is the last thing to flicker away, and just before his body melts into shadow, Dean could swear he feels an answering embrace.

Later, Sam will tell him about vanquishing Osiris, and Dean will tell him that Jo left, happy, at peace.

He won't say that Castiel was dragged back to whatever Hell he's locked in now. Won't tell him about the illusion of Hell.

Why bother? Hell is a yawning chasm, and he carries it with him always. It's a constant.

Castiel had known that.

Castiel had understood.