Hoping to cause a sensation in the field of parapsychology, Dr. John Montague rents Hill House, a secluded manor with a reputation for being haunted. He carefully selects two participants for his study—Eleanor Vance, a thirty-two-year-old woman who was reported to have had experiences with a poltergeist as a child, and Theodora, a woman marked in one of his lab’s studies as having psychic abilities. A third participant, Luke Sanderson, also joins the group. Luke stands to inherit Hill House after his aunt dies, and Luke’s aunt sends him to watch over the house and deter amateur ghost hunters. She also wants to keep Luke out of trouble since he is a liar and a thief.
Eleanor arrives at Hill House first. An instinct tells her to leave, but she stays and meets the house’s caretakers, Mr. and Mrs. Dudley. They are unwelcoming and urge her to go away, saying that they refuse to stay at the house after dark. Theodora arrives next, and Eleanor, a recluse, feels immediately drawn to Theodora’s warm, witty, and open personality. Eleanor lies and tells Theodora she has an apartment back home, when she actually lives at her sister’s house, where she sleeps on a cot. Eleanor was her mother’s primary caretaker up until her mother’s death a few months prior. She is just beginning to explore her freedom and is elated to have found a new friend.
Dr. Montague and Luke arrive next. Dr. Montague reluctantly tells the group about the house’s history after dinner—he doesn’t want to scare anyone into leaving, since the last tenant to leave at night died when his horse crushed him against the oak tree in the driveway. Dr. Montague explains that the house was built eighty years ago by a man named Hugh Crain. Crain designed Hill House as a series of cloistered, maze-like concentric circles that are almost impossible to navigate. Tragically, Crain’s wife never set foot into the house; she died when her carriage overturned in the driveway. Bitter and depressed, Crain stayed to raise his two daughters in the house. Over the years, the daughters fought over ownership of the house, and the house eventually landed in the hands of the older sister’s caretaker, a young woman from town. Taunted and harassed by the younger sister and the townspeople, the young woman hanged herself, reportedly in the house’s turret.
Over the first week of their stay, the group experiences a series of unexplainable events. One night, the women hear a loud banging on the door and feel a chilling breeze. The men see a mysterious animal run down the hallway. Outside the nursery, they discover a mysterious cold spot. Inside the library, Eleanor detects an awful odor. Finally, Luke discovers the words HELP ELEANOR COME HOME written in chalk in the halls. With each event, the group grows more suspicious of Eleanor, and Eleanor is terrified by the thought that the house is singling her out.
The odd events continue. When Theodora finds the words HELP ELEANOR COME HOME ELEANOR written in blood on her walls, she lashes out at Eleanor, who she suspects is doing these things to get attention. Meanwhile, Eleanor feels herself losing grasp of her senses and at the same time becoming more connected to Theodora. At one point, Dr. Montague assures everyone that ghosts can’t cause them physical harm—only fear can do that. Still, Theodora and Eleanor continue to experience strange events that are hard to recall yet hard to deny.
Mrs. Montague, a parapsychologist, arrives at Hill House with her friend, Arthur. Belittling her husband and his lack of progress, she confidently declares that she will draw out Hill House’s spirits. Mrs. Montague believes that spirits feel lonely and want to connect, but they need to be coaxed into communicating. To accomplish this, she uses a device called a planchette. Mrs. Montague reports that a spirit named “Nell” spoke to her, saying it wanted to go home. The group, deeply disturbed, continues to watch Eleanor with suspicion while growing more fearful of the house. That night, Dr. Montague, Luke, Theodora, and Eleanor stay in a room together to keep watch. They hear terrible banging sounds on the door while Mrs. Montague and Arthur sleep in nearby rooms, undisturbed.
Eleanor realizes that she can hear any sound that occurs inside the house, no matter which room she is in. She believes that she is merging with the house and can sense things that the others can’t. Eleanor wakes up one night and goes to the library, aware that she’s not acting entirely of her own volition. She hears a voice that sounds like her mother’s and chases it throughout the house. Trying to avoid the others, who now realize that she’s roaming the house alone, Eleanor retreats back to the library and climbs a rickety iron stairway to the turret. The others gather underneath it and worry that the stairway will collapse, but Luke climbs up and ushers Eleanor back down to safety.
The next morning, the group agrees that Eleanor must leave Hill House. Eleanor cries and says she has nowhere to go, claiming that Hill House is now her home. Dr. Montague, worried for Eleanor’s sanity, says she must leave at once. Eleanor finally agrees, and the group watches as she begins to drive down the driveway. As she departs, however, Eleanor pities the group for believing that they can thwart Hill House’s desire to keep her—she believes that she belongs to the house. She accelerates toward the oak tree, and right before she crashes and dies, she wonders why she is doing this and why no one is stopping her. After Eleanor’s suicide, the group leaves Hill House. Dr. Montague later publishes his study, but his colleagues ridicule his findings.