Plot
Tom Witzky is a phone lineman living in a working-class neighborhood in Chicago with his pregnant wife Maggie and his son Jake, who possesses the ability to communicate with the dead, although neither Tom nor Maggie yet know about it. At a party one evening, Tom challenges Maggie's sister, Lisa, who is a believer in paranormal activity, to hypnotize him. After putting him under, Lisa plants a post-hypnotic suggestion in Tom urging him to "be more open-minded". Tom then begins experiencing visions of a violent scuffle involving a girl who he learns is Samantha Kozac, a 17-year-old who disappeared from the neighborhood six months earlier and had an intellectual disability, with the mental capacity of an eight-year-old and thus a child's tendency to trust strangers.
While Tom and Maggie attend a high-school football game, Jake is overheard by his babysitter, Debbie, as he speaks with Samantha. Debbie gets upset and snatches Jake, running off with him in the night. Tom senses Jake is in danger and sees strange flashes of red light that lead him to the Metra station where Debbie is speaking with her mother about Jake. When Tom and Maggie confront her and with a police officer now present, Debbie angrily questions them about her sister Samantha, explaining that she ran away from home.
Tom becomes obsessed with Samantha and begins probing members of the community about her disappearance. This attracts the attention of his landlord Harry Damon, Tom's friend, Frank McCarthy and their respective sons Kurt Damon and Adam McCarthy, who all dismiss Samantha as a runaway teen. After another prophetic vision in which Frank tells Tom that "they're going to kill you and Maggie both," Tom finds that Adam has shot himself in Frank's home and is in critical condition.
During an afternoon walk, Jake and Maggie encounter a funeral where Chicago policemen are saluting in a ceremony; a policeman named Neil recognizes Jake's unique talent and invites Tom to a private gathering of like-minded people to learn more about what is happening to his son. Maggie goes to the meeting herself, and Neil tells her the spirit that contacted Tom has asked for something and will grow upset if it does not get done. As predicted, Samantha begins plaguing Tom, leading to his insomnia. Samantha tells him to dig. Tom complies and digs holes in the backyard and tears up the house in a desperate attempt to appease Samantha.
While Maggie and Jake attend her grandmother's wake at a relative's house, Tom inadvertently knocks down a shoddy brick wall in the basement and discovers Samantha's mummified remains. He receives a vision showing him that before his family moved in, a drunken Adam and Kurt lured Samantha into the house to rape her. When she resisted and began to scream, they smothered her to death and hid her body. Tom brings Frank back to the basement to disclose to him the crime. Frank breaks down and admits that Adam and Kurt had confided their secret to him and Harry, and that they had helped cover up their sons' crime. Frank pulls out a gun and demands to be alone. As Tom leaves, he hears a single shot.
Harry and Kurt arrive and corner Tom with the intention of killing him, but Maggie interrupts. As Harry takes her hostage, Frank emerges and fatally shoots Kurt and Harry. Tom notices Samantha's spirit smile and disappear. Afterward, the family moves out of the house. Samantha's mother and sister are able to give her a proper burial. Jake covers his ears as his family approaches their new home, overwhelmed by all of the spirits that linger in the houses they pass by.