A dysfunctional family moves into the infamous Long Island property, where the teenage son falls under the influence of sinister forces, causing him to form an incestuous relationship with his sister and ending in a frenzy of murder. The authorities look on the boy as a cold-blooded killer, but a kindly priest knows he is not responsible and battles to save his soul. Horror prequel, with Burt Young, Jack Magner and James Olson.

Anthony and Dolores Montelli, along with their four children, move into their dream house in Amityville and are immediately plagued by a string of paranormal experiences. When the abusive Anthony wrongly places the blame on the children, Dolores recruits a local Catholic priest to exorcise the house.