This hysterical horror film was the most successful of numerous Italian possession films produced in the wake of The Exorcist. Lead Juliet Mills (Nanny and the Professor) was married to co-screenwriter Roberto d'Ettore Piazzoli at the time, which might explain her willingness to curse in a guttural voice, spin her head, and throw up in this crude and sexist film. Mills plays the cheating wife of San Francisco record producer Gabriele Lavia (Profondo Rosso) and gets pregnant after a fling with Richard Johnson. What Mills doesn't know is that Johnson is a Satanist, and she is bearing the Antichrist. Child star David Colin, Jr. returned in the otherwise unrelated Beyond the Door II, while director Ovidio Assonitis went on to rip off Jaws with the giant octopus-epic Tentacoli.