An obsessed scientist conducts profane experiments in evolution, eventually establishing himself as the self-styled demigod to a race of mutated, half-human abominations.

14-year-old Lulu moves to a small provincial town with her mother and younger brother. One night, her brother is struck by a beam of white light - actually the spirit of Herman Hartmann from the 19th-century. To her despair, Lulu realizes that Herman has possessed her brother, and the two of them are whirled into a fevered adventure.

Rene Cardona directs the film version of Jose Leon Sanchez's best-selling novel, which relates the author's 20 years of imprisonment on an island ruled by brutality. When a sadistic man declares himself the boss of an island pueblo, an innocent husband and wife become the victims of his selfish rule. Once the evil man's deeds reach the authorities on the mainland, however, he sinks further into madness and declares "his" island its own republic.