After the massacre at the ranch, Dean, Sam, and Castieldouble their efforts to find a cure for the Mark of Cain butthere is nothing in the lore that can help them. Desperate,Castiel comes up with an idea that Sam deems the "single worstidea I've ever heard." Meanwhile, Rowena continues to plotagainst Crowley, and Castiel tries to mend his relationshipwith Claire who is plotting revenge against Dean for killingher friend.
