Giulio Berruti's unusual cult horror film casts former sex symbol Anita Ekberg as Sister Gertrude, a nun working in a mental institution. Gertrude is clearly insane, and takes a great deal of morphine for her self-diagnosed cancer. She goes to town and picks up men, seduces a younger nun (Paola Morra) who was abused by her grandfather, and supposedly murders patients until the Mother Superior (Alida Valli) has her poisoned. Luigi Casellato appears as a crippled painter who gets kicked to death, and genre favorite Joe Dallesandro leads the supporting cast as a handsome doctor. Antonio Maccoppi's skillful cinematography gives the film a harsh, intimidating look and Ekberg creates a sympathetic character, although certain scenes -- such as her stepping on a patient's dentures -- cross the line into unintentional humor.