In 1945, Grace Stewart occupies a remote country house in Jersey and awakens one day from a nightmare in the immediate aftermath of World War II. She lives with her two young children, Anne and Nicholas, who have a rare disease characterized by photosensitivity (possibly xeroderma pigmentosum). Grace hires three new servants—the aging Mrs. Bertha Mills, elderly gardener Edmund Tuttle, and a mute girl named Lydia. Mrs. Mills explains to Grace that she worked in the same house many years before. When odd events occur at the house, Grace begins to fear there are unknown “others” present. Anne claims to have seen a group of people in the house several times: a man, a woman, an old woman and a child called Victor, who claimed that “the house is theirs”. After Grace hears footsteps and unknown voices, she orders the house to be searched. Grace finds a 19th-century “book of the dead”—a photo album of mourning portrait photos. When Grace asks Mrs. Mills about her previous experience in the house, Mrs. Mills recounts that many left due to an outbreak of tuberculosis.
At night, Grace witnesses a piano playing itself and becomes convinced that the house is haunted. She runs outside in search of the local priest to bless the house. Before leaving, Grace instructs Tuttle to check a small nearby cemetery to see if there was a family buried there who had a little boy named Victor. Tuttle finds the cemetery but, per Mrs. Mills’s orders, covers the gravestones with leaves. Mrs. Mills assures Tuttle that Grace will learn in due time the reasons behind the unexplained events. Outside, Grace runs into her husband Charles, whom she thought had been killed in the war. Charles greets his children after a long absence, but is distant during his short stay at the house. Later, Grace comes across an old woman in one of the rooms and attacks her. The old woman is only a vision and Grace has in fact attacked her own daughter, Anne. Later, Anne tells her brother that their mother went mad in the same way “that day” but he does not remember. Charles says he must leave for the front, even though Grace claims that the war is over. The two embrace and lie motionless together in bed.
The next morning, Charles has left and the children are screaming that the curtains are gone, letting in sunlight. Grace accuses the servants of removing the curtains and banishes them from the house. That night, the children sneak outside and discover that the headstones in the cemetery belong to the servants. The children retreat in fear when they see the servants approach. Meanwhile, Grace finds a photograph that has fallen out of the book of the dead onto the floor under some furniture. It is a photograph of the corpses of the three servants. The children run upstairs and hide in the bedroom where they are discovered by the elderly woman. Mrs. Mills returns to the house and tells Grace to go upstairs and talk to the intruders. Grace discovers that the old woman is in fact a medium in a séance with Victor’s parents, who has found out via automatic writing that Grace smothered the children to death with a pillow in a fit of rage before committing suicide. Grace realizes that the “others” are the family that has moved into the house, and that she, her children and the servants are dead. Following this display of supernatural activity, Victor and his family vacate the house and leave it in the occupancy of the ghosts.