Season One consists of 22 episodes that aired in the United States beginning September 13, 2005, and ending May 4, 2006. The first sixteen episodes aired on Tuesdays at 9:00 pm, after which the series was rescheduled to Thursdays.
Two brothers, Sam and Dean Winchester, team up to find their father, John, who went missing on a hunting trip. However, their father isn't a typical hunter: he hunts supernatural creatures like ghosts, vampires, and various demons and he's trained his sons to do the same. Along the way, Sam and Dean save innocent people, fight creatures and ghosts, and collect clues to their father's whereabouts. Sam begins to mysteriously develop psychic abilities and visions as they travel. They eventually find their father, who reveals that the creature that killed Sam and Dean's mother years earlier is a yellow-eyed demon and the only thing that can kill him is a legendary gun created by Samuel Colt.