The rich owner of a rubber plantation is murdered by his steward who has fallen in love with the elderly landowner’s beautiful wife, played by Barbara Payton. The steward, played by Burr, soon has married the widow of his victim. One of the trusted servants of the old master, a man who knows the art of voodoo, saw the crime, though, and curses the steward. Because of the curse, the steward turns into a vicious gorilla at night and attacks the local villages. The local policeman, played by Lon Chaney Jr., investigates the attacks.