A mad scientist uses radiation brainwaves to transform humans into cannibalistic monsters. The plot is a mixture of frights and sensuality as Blood Island chiefs sacrifice beautiful young virgins to "The Evil One" - a horrid creature, bred by radiation, and like a werewolf, metamorphosed from an innocent man. Coming to this island are scientists Kent Taylor and John Ashley, along with Taylor's beautiful wife, played by the alluring Beverly Hills. Taylor and Hills search the jungle for evidence of mutated lifeforms as they are attacked by living vegetation and frightening animal life. The films climax ends in a burning inferno as the evil creature attacks villagers and scientists, who are unprepared to combat this inhuman monster.