Dr. Edward Fitzgerald is a brilliant psychologist who freelances his services to the police as a criminal profiler. In a blood-soaked alleyway, Fitz tells detectives that the killers of a loan shark are sure to be a young man and woman using sex as a weapon and murder as an aphrodisiac. But there's one thing Fitz can't tell them--the pair are on to their next crime, and a cop is going to die.