Sam tries to figure out what has happened to Dean, who is now a demon running around with Crowley; Castiel faces his diminishing grace.
Crowley notices Dean's increasing level of aggression; a vengeful man named Cole captures and tortures Sam.
Sam works to save Dean from the mark of Cain; Crowley seeks the help of an unexpected ally -- Castiel.
A series of attacks lead to a surprising culprit -- a werewolf named Kate who was left alive by Sam and Dean.
As Sam and Dean investigate a teacher's disappearance, they are stunned to learn that the school is presenting a musical based on their lives.
Dean and Sam go to claim their fortune after discovering that Bobby or his next of kin have been named as a beneficiary in an heiress' will.
Jared Padalecki
Sam Winchester
Jensen Ackles
Dean Winchester
Misha Collins
Castiel
Alexander Calvert
Jack
Mark Sheppard
Crowley