The crackle and flash of Peacemaker's power burns under the demon's skin the same way he's seen with the Colt both he and Dean know, then winks out along with the demon's existence... and the life of the woman she'd been riding.

Sam stares down at the body in grim silence, shoving his guilt away. They'd had to be sure. He'd had to be sure. She was probably damaged enough not to live through it anyway, the same way Meg had been, and half of the people the Sins had possessed. Probably.

After a second or two longer, he glances at Wynonna. "I've got salt and gasoline in the car." Low and a little unsteady, but determined. "You can wait there while I take care of the body."