In 1971, Roger and Carolyn Perron move into a dilapidated farmhouse in Harrisville, Rhode Island with their five daughters Andrea, Nancy, Christine, Cindy, and April. During the first day, their move goes smoothly, though their dog Sadie refuses to enter the house and one of the daughters finds a boarded up entrance to a cellar.
A few paranormal events happen within the first few nights, including all of the clocks stopping at exactly 3:07 AM and Sadie being found dead in the back yard. One night, while they are both in bed, Christine feels a tugging on her leg, which she first expects to be Nancy, but is a spirit only she can see. She begins to scream and tells her family that the spirit wants the family dead. Carolyn is folding laundry in the night when she hears clapping in the hallway. When she goes to investigate, all the picture frames along the wall fall and shatter on the floor. She goes downstairs following laughter and finds the basement door opening slowly. When she goes inside to investigate, she’s trapped there by the spirit who claps beside her as her matchstick flickers out. At the same moment, Andrea and Cindy are attacked by a spirit on top of the wardrobe.
Carolyn decides to contact noted paranormal investigators Ed and Lorraine Warren, who agree to take on the case. The Warrens conduct an initial investigation and conclude that the house may require an exorcism, but they need authorization from the Catholic Church and further evidence before they can proceed.
While researching the history of the house, Ed and Lorraine discover that the house once belonged to an accused witch, Bathsheba (a relative of Mary Towne Eastey), who sacrificed her week-old child to the devil and killed herself in 1863 after cursing all who would take her land. The property was once more than 200 acres but has since been divided up into smaller parcels. They find reports of numerous murders and suicides in houses that have since been built upon parcels that were once part of the property.
Ed and Lorraine return to the house to gather evidence to receive authorization for the exorcism, placing cameras and bells around the house. A bell goes off near Cindy after they finish setting up. They catch a glimpse of Cindy sleep walking into Andrea’s room, and from the EVPs coming from the radio, they hear a spirit luring Cindy into the wardrobe, where she reveals a secret passage inside. Lorraine enters the passage and falls through the floorboards into the cellar, where she sees the spirit of a woman whom Bathsheba had long ago possessed and used to kill her child. Another of the Perron children, Nancy, is violently dragged by her hair along the floor by an unseen force.
The Perron family decides to take refuge at a hotel while Ed and Lorraine take their evidence to the Church to arrange an exorcism. While the Warrens are on their way home, their daughter Judy is attacked in their own home by the spirit of Bathsheba, along with the haunted Annabelle doll from the Warrens’ previous case, though Ed arrives in time to prevent her from being harmed.
Carolyn, now possessed by the spirit of Bathsheba, takes two of her daughters, Christine and April, and drives back to the house. Ed, Lorraine, Roger, their two assistants, and a police officer rush to the house where they find Carolyn in the cellar trying to stab Christine with scissors. After subduing Carolyn and tying her to a chair, Ed decides to perform the exorcism himself. Though Carolyn escapes and attempts to kill April, who is hiding under the floorboards, Lorraine is able to temporarily distract 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 April.
Returning home, Lorraine tells Ed that the priest whom they sought for the exorcism had called back and left a message, saying that he had gained approval from the Catholic Church to perform it. In addition to this, he also hasanother case for them to investigate on Long Island. When they leave, the music box that April had found opens and plays music as the camera lingers on it. Once it stops, the screen cuts to black.