Something's not right. It's not just in Dean's words, almost unintelligible under the agony, it's in how everything feels, every hair on his arms and the back of his neck lifting. More even than the waves of wrongness that have been slamming into them all since they got here.

He's not even sure he would call this wrong. It doesn't feel wrong.

It feels like power.

He glances back at Sam, doesn't know how to make sense of what he's seeing - but he doesn't need to understand it. Castiel has told him. There's no fucking time.

He grips the knife and drops into a crouch, looking for the brand on Dean's foot.