In 1971, Carolyn and Roger Perron move into a dilapidated, old farmhouse in Harrisville, Rhode Island with their five daughters. During the first day, the family moves in smoothly, though the dog refuses to come into the house and one of the daughters finds a boarded up entrance to a cellar. The next morning, Carolyn wakes up with a mysterious bruise and the dog is found dead. Over the next several days, various paranormal activities occur. The activity culminates one night while Roger is away in Florida, as Carolyn is locked in the cellar while a spirit that looks like an elderly woman attacks one of her daughters. Carolyn contacts noted paranormal investigators Ed and Lorraine Warren for help.

The Warrens conduct an initial investigation and conclude that the house may require an exorcism, though this cannot be done without further evidence and authorization from the Catholic Church. While researching the house's history, Ed and Lorraine discover that the house once belonged to an accused witch, Bathsheba, who killed herself after cursing all who would take her land. They also find reports of numerous murders and suicides in houses that have since been built upon the property. Ed and Lorraine return to the house in an attempt to gather evidence to receive authorization for an exorcism. That night, one of the daughters sleepwalks into her sister's room and reveals a secret passage behind a wardrobe.


Lorraine enters the passage and falls through the floorboards into the cellar, where she sees the spirits of people whom Bathsheba has possessed. All are mothers whom Bathsheba used to kill their children. Lorraine and Ed take their evidence to the Church to organize an exorcism while the Perron family takes refuge at a hotel. A possessed Carolyn takes two of her daughters, Christine and April, and drives back to the house. Ed and Lorraine rush to the house where they find Carolyn trying to stab her daughter. After subduing Carolyn, Ed decides to perform the exorcism himself, though Carolyn escapes and again attempts to kill her daughter, April. Lorraine is able to stop the possessed Carolyn from killing her daughter by reminding her of a special memory she shared with her family, allowing Ed to complete the exorcism, saving Carolyn and her daughter.