Dean reads in the newspaper about the mysterious death of a man who was slaughtered inside a locked room in a farm in the countryside of Stratton, Nebraska. The Winchester brothers travel to the house, believing it to be a typical ghost case. They expect to find the house empty but meet the Carter family who has just moved to the country expecting to rebuild their lives after a tragedy. They discover that the victim had lost his wife in childbirth and his daughter hanged herself in the attic twenty years ago. When the family is attacked by the same mysterious creature, the brothers protect the family with a circle of salt; however, she easily crosses this protection, and they realize that she is not a ghost or demon. What is the creature? Can Sam and Dean rescue the young son trapped with the creature within the walls of the house in time?