A mythical monster turns men to stone in a remote European village.
Many petrified corpses are found in the village of Vandorf in 1910. When Bruno Heitz, an artist, is found hanging from a tree following the death of his girl friend, he is assumed to be the murderer. Attempting to clear his son's name, Professor Heitz visits Vandorf, where he encounters the hostility of Police Chief Kanof, brain surgeon Namaroff, and the villagers themselves, who set his lodgings ablaze. In the ruins of Castle Borski the professor confronts Megaera, the legendary gorgon. Her gaze gradually turns him to stone, but he notifies his elder son, Paul. Accompanied by his mentor, Professor Meister, Paul arrives in Vandorf. When Namaroff refuses to see him, Meister's suspicions are aroused. Aware that Paul is attracted to Carla, Namaroff's assistant, Meister advises him to shun her. From Namaroff's papers Meister learns that Carla, an amnesiac, is the surgeon's former patient. Discovering that Paul and Carla have arranged a tryst at Castle Borski, Meister rushes to the ruins. There he and Paul slay both Namaroff and Carla, whose body had housed the gorgon.
