Sexual maniac Romeo terrorizes San Francisco. The bloody murders are shocking in their cruelty: the criminal places the half-decayed heart of the previous victim on the tortured troupes. Psychologist Melanie Rosen publicly challenges the villain - elusive, cynical, calculating - and falls into his trap. But this is not the last victim; her sister Sarah is next. Romeo does not let her go, keeps her in constant fear. And there are so many people around trying to help, and everyone can be a potential killer, even the one she fell in love with...