Seeking to cure his rare blood disorder, Dr. Michael Morbius instead cursed himself with an insatiable lust for human blood. While trying to cure his horrific condition, he has become allied with Amanda Saint, whose sister Catherine is one of the leaders of the Demon-Fire Cult. Also known as Poison Lark, Catherine Saint has two goals above all else. She seeks to bring Satan to Earth, thus unleashing the powers of Hell, and to kill Morbius and Amanda. When Morbius and Amanda follow the cult's trail to New York City, they run afoul of an underground fight club that uses monsters as their pawns in the arena. The club captures Morbius and he becomes the star attraction, forced to kill or be killed.