A psychiatrist (Bernard Letrou) ventures to a remote castle to convince a brood of four vampire sisters that they are misguided, brainwashed by superstitious villagers, and not truly creatures of the Supernatural. The villagers (including director Jean Rollin) confuse and abuse the sisters, before finally storming the castle. The cast descends on a hospital run by a young doctor (Jean-Loup Philippe), charged by the Queen of the Vampires (Jacqueline...

Still reeling from the heartbreaking death of their mother, a teenage girl and her younger sister find themselves hounded by a sadistic presence in their house and struggle to get their grieving father to pay attention before it's too late.