Guided by Sam's vision, Sam and Dean return to the house where they spent their childhood. A mother and her child are being tormented by a mysterious phenomenon. The brothers think that it may be the doing of an evil spirit, so in order to find some clues they visit Missouri, a spirit medium who was close to their father. With the help of Missouri they succeed at exorcising the evil spirit. However, on the same night the mother and her child are once again attacked by a violent poltergeist phenomenon...