Karnstein Castle stands like a bird of prey on the highest point of the hills that surround the village below. A huge monolithic reminder to all those who see it of the power of the family who have lived there for centuries.

By day the village of Karnstein is a peaceful place, but by night, an unimaginable evil roams free. Villagers are found dead, their throats ripped open and bodies drained of blood. Young girls disappear and are never seen again. Rumour has it that they are taken to the castle for the pleasure of Count Karnstein, the last surviving member of the family.

Into this strange place, come beautiful identical twins Maria and Frieda. While Maria lives a blameless life, Frieda is drawn to the castle and Count Karnstein. A man rarely seen in daylight, a man steeped in Satanic ritual and the blood of beautiful young girls.

Before long Frieda and Karnstein unleash a reign of bloody terror on the villagers, and no one, it seems, is strong enough to stop them.