The place is a bloodbath and most of it is on Dean; red liquid streaming down his face, dripping down the deathly bone in his hand. And not a drop of it is his. He's boiling with rage, the inconceivable power.

"Dean, stop!" Cas shouts, but it doesn't help; the damned man's knuckles go white. "Dean, you can fight it! It's inside you, but this is not you"

Dean keeps coming closer, although there is no one left to fight: Abaddon, Crowley, Cain – they're all dead. Gadreel, with his broken caricature of wings burned on the wall, Metatron, gutted in the corner like a pathetic garbage that he was. Dean keeps coming closer. His eyes are pitch black, blacker than your regular run-of-the-mill demon's, blacker than hell.

"No, Dean!"

Cas doesn't even feel pain when the bone thrusts into his stomach, he just stares into those eyes trying to wish the black away; he touches this face that he somehow managed to cup with his numbing hand.

"I love you, Dean," he sputters with the blood flooding his mouth. "I always have."

Something snaps in Dean as he rips the blade out, and, even if for a moment, his eyes turn green again – the sweetest green Cas's ever known. His murderous hands catch the angel as he falls.

"Cas, no! Cas!" he cries, his voice shattered. "What have I done? Cas!"

"It's okay," Cas mutters, struggling to get the words out, but he must get them out. "It's not your fault, it's okay, Dean."

But it's not okay. Dean's right hand cradles his head, with the other one he clutches to the trenchcoat with his whole life. Warm breath brushes over Cas's face, lips pressed to his forehead tremble with a prayer of no, Cas, you can't, Cas, what have I done?

"It's not your fault," he whispers once again, but he's not sure if Dean hears him anymore.

And he's not sure, when he drifts off into eternal darkness, if the soft, broken words he hears are real:

"I love you, too, Cas."

I always have.