After Chuck brings on the end breaking open the gates of hell, Sam, Dean, Castiel deals with the after effects dealing with a horde of zombies and ghosts. Sam meanwhile, discovers through nightmares and flashes of what he believes are God's memories that he's connected to Chuck through the gunshot wound that's not healing. While this is all going on Sam deals with his guilt from killing Rowena while also becoming close to Eileen, after he resurrected her with a spell.