After receiving a frantic call from Sam (Jared Padalecki), who has been missing for over a week, Dean (Jensen Ackles) races to his brother’s side. He finds Sam covered in blood, but unable to remember anything that happened.
Upon investigation, the brothers are horrified to discover a tape that shows Sam killing another hunter in cold blood, causing Sam to believe his evil side is finally taking over.
Cathryn Humphris wrote the episode directed by J. Miller Tobin.