American horror in which newly-weds George (James Brolin) and Kathy (Margot Kidder) take the lease on a beautiful colonial house on Long Island and move in to discover foul odours, slamming doors, and the occasional very violent bump in the night. As the months pass it becomes clear that the house is in the grip of some kind of supernatural possession, and as the unworldly incidents become more and more troubling, a priest (Rod Steiger) is called in to set things right.