Following visionary Sam's recent nightmare about the former Winchester home in Lawrence, Kansas, where the present dwellers, Jenny from Wichita and mother to two small kids, are suspiciously accident-prone, Dean reluctantly accepts to drive there. Dean and Sam reassure Jenny but follow up on the kids fear of a flaming creature in the closet. They consult Missouri Moseley, their father John's old medium friend, and together with the spirit of Mary Winchester, confront an evil poltergeist, but a second ghost intervenes and someone hides behind Missouri.
Sam has a nightmare that he believes to be a vision of their childhood house and convinces a reluctant Dean that they need to go back home. They soon discover that the new owners are being plagued by what could be the same thing that killed their mother 22 years ago.
When Sam starts to have nightmares about their old home, he and Dean head back to Kansas. They soon discover that the new owners of their old house are being plagued by a malevolent entity, could it be the same thing that killed their mother many years earlier?
Sam has a nightmare with the dwellers of his former house in Lawrence, and convinces Dean to drive to Kansas. They meet Jenny, who has just moved from Wichita and tells them about the weird noises in the house, and her daughter, who tells about a flaming creature in the closet of her room. Dean and Sam bring the old medium friend of their father, Missouri Moseley, and together with the spirit of Mary Winchester, they battle against an evil poltergeist.
- The new residents of the Winchesters former home in Lawrence, Kansas, a young mother, Jenny, and her two children, encounter strange noises and visions in their new house. Elsewhere, Dean () looks for cases while Sam () draws the same tree over and over, and suddenly realizes that it is the tree from outside their childhood home. He tells Dean urgently that they have to return to Lawrence because the new owners are in danger, and when Dean presses him, he admits that he dreamed about it, and explains how his nightmares sometimes come true, like in the case of Jessica's death. Dean is uncomfortable with the idea, but the nevertheless journey to Lawrence and go to the house. When she asks, Sam interrupts Dean's fabricated story and tells Jenny truthfully who they are, and asks the see the house for nostalgia's sake. She tells them about finding the old photos and invites them in, where they meet her children, Sairie and Ritchie. When the brothers ask, Jenny admits the house "has its issues" and explains about the flickering lights and strange sounds, and they understand that to mean that there is a spirit or presence in the house.
Outside, Dean and Sam speculate that the being in the house might be the same thing that killed their mother ) and Jessica (), and decide to continue their father's research into their mother's death. Dean calls John () yet again, leaving him an emotional message and begging him to come back and help them. The brothers then talk to an old friend of John's, a garage owner, who says that John became obsessed with investigating Mary's death and eventually consulted a palm reader for help. The brothers discover in John's journal that the psychic is named Missouri Mosely (), and when they go to visit her, it is immediately apparent that she is the real deal. She remembers Mary's death, but says she could not identify what killed her, saying only that it was exceptionally evil.
Meanwhile, the house continues to exhibit hostile energy, grievously injuring a plumber who comes to fix the sink. Later, the refrigerator opens on its own and when little Ritchie crawls inside, it closes and traps him there, scaring Jenny. Sam and Dean then bring Missouri to the house, and she reports that there is more than one spirit in the house because the house is now a "magnet" for otherworldly activity ever since Mary's death, and says that one of them is a malevolent poltergeist, although it is not the thing that killed their mother. She and the boys attempt to purify the house with the help of special ingredients, urging Jenny and the children out of the house while they work. They are soon attacked by the spirit, however, and Sam is nearly strangled, but Dean helps him and the purification seems to have worked, although it causes excessive damage and mess to the house. Jenny and her children return, believing the house safe, but later that night, Jenny's bed begins to shake violently, revealing that the poltergeist is still present. Sam and Dean, who were keeping watch outside just in case, run into the house and rescue the family, but Sam is trapped by the spirit. Dean breaks back into the house just as a fiery figure appears, but Sam cautions him not to shoot at it, and a moment later, it resolves into the form of Mary.
The boys are stunned to see her, and she smiles sadly at both of them before apologizing to Sam, banishing the poltergeist from the house and disappearing in a rush of flame. Later, Missouri says that Mary's spirit destroyed itself to get rid of the poltergeist, and she and the brothers leave Jenny and her family in peace. Sam asks Missouri if she can explain what is happening to him with his strange, prophetic dreams, but she admits that she doesn't know. Returning to her home, Missouri muses that even with his strange powers, Sam could not sense his father's presence, and it is revealed that John has been there all along. She urges him to talk to his children, but he refuses, saying that he needs to find out the truth about their mother's death first.