Overcome with passion and desire for the beautiful and sultry Dina Van Gelder (Barbara Payton), plantation manager Chavez (Raymond Burr) is driven to murder her husband. Having spurned one of the locals for the sensual blond, he becomes the victim of a curse by a voodoo priestess. "He shall be like an animal," she proclaims, thereafter transforming him into a gorilla whenever he enters the jungle. Lon Chaney, Jr. stars as the local commissioner with a respect for native superstitions who attempts to provethat Chavez is a murderer. This ultra-serious, grade B horror film by Curt Siodmak delivers another view of the metamorphosis he made so famous with the masterpiece The Wolf Man.