Is there such a thing as 'good' and 'bad' twins? Psychobiologist Dr. Jeannie Ferrami (Kelly McGillis) thinks she's found living proof in the form of 'good guy' Steve Logan (Jason Gedrick) and his twin Dennis, who's in jail for murder. As her boss tries to discredit her research, Jeannie digs deeper - only to be brutally attacked by a man who looks just like Steve. Could this attractive, likeable man be a rapist and killer? Or could the Logan brothers have what should be a biological impossibility: a 'third' twin?