The movie begins in the year 1978, where Ed and Lorraine, who are the paranormal investigators are working on their new case. They are documenting the murders at the Amityville house, to determine if there is any demonic presence in the house that has led Ronald DeFeo Jr. to murder his entire family. During the investigation, they try to make contact with the dead and in this séance, Lorraine is drawn into a vision, where she could see the murder happening and notices that there is a demonic nun behind all this.
Ed brings her out of the vision after striving hard. A year later, Hogsdon family, living in London notices the strange things happening in their home. They see their second child’s behavior has changed as she is seen walking in sleep, talking to someone in sleep who claims that it’s his house. Realizing that there is possessed with a demon, the parents contact a local church, who in turn calls Ed and Lorraine to help them in the investigation.