Plot
A young couple, Sara and Alex Davis, arrive at a farmhouse in the countryside with their infant son, Liam. They seem to be shifting away from the city, and the farmhouse instantly seems like the ideal choice. Sara, however, seems to be struggling to manage her incessantly crying baby and is distant at times. Alex makes up for her silence as he looks around the property, which has a big house and barn. As the paperwork is about to be finalized, Sara asks the realtor why the house has not had anyone living in it for a long time, to which she frankly responds that there had been some gruesome incident in it many years back. Alex says that they do not want to know about it, but Sara insists that they should, and the realtor reveals that a girl had committed suicide in the house after killing her baby and father. She hands them an enveloped report and suspects that the couple will also obviously skip the property, much like everyone else before them. But Sara says that they still want to take it and even tells her husband that she would not mind a little haunting.
Sara most struggles to be close to her son, who also seems to not want to be breastfed and instead prefers milk from a bottle. Alex, a veterinarian, often works long days, leaving Sara alone with Liam. She and Alex find a locked room in their new house, which they open and to find a child's room, presumably the girl's. As they are exploring, a man arrives and scares them. He says his name is Chris Renner, and he lives next door. He is helpful, fixing things around the house for Sara and telling her what really happened in there. Sara also opens the envelope and reads up about the incident: a young girl, Anna Solomon, used to live with her father, Robert, in the house, who she murdered along with her own child, before killing herself some forty years back.
Sara begins to hear and see things in the house. It is revealed that she is suffering from postpartum depression, which leaves her feeling distant from her husband and son. She hears children laughing and playing behind a locked door that has been hidden by a heavy wardrobe. Chris tells Sara that Anna had a brother, their mother had died in childbirth, and that Robert had been raping Anna. When Sara asks what happened to the brother, Chris says he was ignored and blamed for his mother's death. Sara reveals to him that she's seen both Anna and Robert in the house; Chris says he doesn't believe in such things and leaves. Sara invites the realtor over to ask what happened to the boy, and the realtor tells her it is Chris; he had tried to assume a new identity when he returned.
Things begin to disappear in the house —- Liam's pacifier and toy truck and Sara and Alex's wedding portrait. He passively accuses her of misplacing them. One night while she is up with Liam, Sara sees Anna lying on a bed with Robert over her, both staring at Sara. She puts Liam down on the floor to investigate. As she is distracted by this, Liam nearly crawls down the stairs. He is saved by Alex. The next morning, Alex tells her he's called a psychiatrist, Dr. Carver and will not leave her alone with Liam for the time being. She tries to tell him that there's a presence in the house, but he remains logical. Dr. Carver arrives and Alex leaves for work. She lies to him when he asks if she's been hearing or seeing things. He wants her to begin taking medication, but she refuses. Sara tells him she feels none of the euphoria of motherhood, which causes her to feel embarrassed and guilty. She's afraid if she takes the medication, she'll never feel a real connection to Liam. She asks him to leave, but he tells her he can't. Chris arrives and tells Dr. Carver he can go. He leaves the pills on the table should she decide to take them.
While Alex is working, Chris stays with Sara and plays with Liam. She asks why he didn't tell her he was Anna's brother. He said he didn't want anyone to know and had just wanted to live close to his home. He cries, and the two share a tender moment. Sara asks if there were other babies before the one Anna killed, and he reveals there were three; he becomes visibly upset and tells her not to bother the wardrobe, that there's a reason it was placed in front of that door, and a reason only Robert could move it.
Sara pretends to take the pills for Alex's sake. One night while the three are taking a bath, Alex receives a phone call and has to leave Sara alone with Liam. She hears stomping in the hallway, and Robert appears, holding her underwater. She resurfaces and he's disappeared. Standing watch over Liam's crib, she hears Anna screaming, presumably in labor, and hears Robert in the hall. She then hears Alex calling to her, thinking he's returned home, and goes downstairs, leaving Liam in his crib. She hears Liam cry, runs back upstairs, and finds the room behind the wardrobe has been opened. All of their missing things are inside. Two dirty boys emerge from the wall, one of them holding Liam. She pleads with them to return the baby, but they accuse her of intentionally hurting her son. One of them raises a hatchet and swings as Sara screams and the screen fades to black.
It is morning, and Sara is holding Liam, repeating happily that he is hers. Alex comes home to his family at the table, breakfast waiting. He sits, and Sara assures him that it's over. After, Liam is growing and they seem happy. Chris teaches Liam to play baseball, and Alex, Sara, and Liam are later seen on a swing with their arms around each other. With her other arm, Sara cradles her pregnant belly (indicating that she's expecting her second child).
