When a doctor (Stelio Candelli) and a young lady (Rita Calderoni) are involved in a car crash, the doctor seeks medical aid at a nearby gothic castle, which he finds inhabited by both his and her darker halves. The two soon encounter their doppelgangers -- and much more. It appears the castle is also full of ghouls and monsters led by Satan himself. Lesbianism, sadomasochism and plenty of nudity make this a classic of 1970s sleaze.