Watching Dean panic like this hurts something deep down inside of Sam and he can't watch his big brother lose it. He shucks his jacket and rolls it up, lifting Cas's head and slipping the makeshift pillow underneath to help the blood slide down his throat instead of pool in the back of it. Castiel's eyes roll to rest on Sam before slipping up beneath his eyelids. He's not doing well.

Something across the room glints star-bright and makes Sam wince, as if someone had just flashed their high-beams in the rearview mirror. "What the hell is that?" he asks quietly, almost to himself, and he stands and crosses the room toward the puddle of Leviathan still steaming.

Picking up a fork from the ground, Sam moves aside a fold of the goo-drenched apron and flinches back when the thing flashes bright again. "Dean-"