Don Massimo (Mel Ferrer) is a nobleman of ancient lineage. For some time he has been having an affair with the lovely Gretel (Anita Strindberg), and his crippled daughter Ippolita (Carla Gravina) is not only aware of the relationship, but disapproves of it in ways which lead him to call for the services of a psychiatrist. The psychiatrist discovers that Ippolita is acting out a family curse from her ancestress, a noblewoman who was burned at the stake as a witch. At this point, the powers of the Church are called on, and the Bishop (Arthur Kennedy) is required to decide how Father Mittner (George Coulouris) and he will conduct an exorcism.