Several years after her first husbands death, Dora (Daria Nicolodi) returns to her country home with her son (David Colin Jr) and her second husband (John Steiner). However, she finds that the house is occupied by a mysterious evil presence that begins to torment her with terrifying nightmares and strange occurrences. Even her young son Mark is grasped by the evil and undergoes hideous transformation as though possessed by a supernatural force. As Dora is driven closer to the edge of madness, the truth behind her first husband's death is revealed. The terror grows as the game of supernatural revenge is played to its chilling conclusion. The final theatrical film from Italian horror maestro Mario Bava.