A teen gives her graduation address and reveals her involvement in the disappearance of one her classmates, a boy who had taunted her. The film then moves into flashback to tell the story.

A group of scientists are trying to produce the perfect soldier by cloning. The day the clone is born, Marty Stillwater, a mystery novel writer, feels that something strange is going on inside his body and mind. Seven years later, Marty discovers that his double has his same physical appearance but has the personality of a murderer.