Supernatural (2005 - Present): Season 4 Promo

Twenty-five years ago, Sam Winchester (Jared Padalecki) and Dean Winchester (Jensen Ackles) lost their mother to a mysterious and demonic supernatural force. Subsequently, their father John (Jeffrey Dean Morgan, "Grey's Anatomy") raised them to be soldiers. He taught them about the paranormal evil that lives in the dark corners and on the back roads of America...and he taught them how to kill it.