S10, E21: Sam and Dean investigate a bizarre murder and realize the killer bears the same tattoo as those from the Styne family. Eldon Styne (guest star David Hoflin) attacks Dean and a brutal fight ensues. Meanwhile, Castiel acts as referee when Charlie and Rowena are forced to work together on the Book of the Damned. Crowley discovers his mother is missing and knows she’s up to something, so he turns to an old enemy for help.