Official Description from the CW

IT'S BOBBY'S WIFE! - Sam (Jared Padalecki) and Dean (Jensen Ackles) investigate Bobby's home town where the dead are rising from the grave but instead of attacking humans, they are happily reuniting with their families. The brothers turn to Bobby (Jim Beaver) for help but he tells them not to worry about it and to leave town. Suspicious, Dean investigates and comes face to face with Bobby's dead wife (guest star Carrie Anne Fleming) who has no memory of what happened to her. Once the zombies start turning evil, the boys tell Bobby he has to kill his wife but he refuses.

John Showwalter directed the episode written by Jeremy Carver.