The Montelli family move into what they think will be the house of their dreams, but there is an evil presence lurking within. Demons terrorize the family, causing them to fall apart. The mother tries to get the local priest, Father Adamsky, to bless the house but he is forced out before he can properly help. The oldest son, Sonny, falls victim to demonic possession. During his possession he gets his sister to play a game where he is a famous photographer and she is his model. She agrees and eventually ends up naked and has sex with him.
The evil spirits cause Sonny to tear the family apart and he is forced to murder his parents and siblings. Father Adamsky realizes Sonny is possessed and asks the church for permission to perform an exorcism but this is refused. He therefore takes it upon himself to free Sonny's soul.