Dennis Pitt is a disturbed young man on parole from a mental institution who becomes attracted to teenager Sue Ann Stepenek. He tells her that he is a secret agent, and takes her along on a series of "missions" that eventually end in murder. While Dennis is racked with guilt over both what he has done and what he has allowed to happen, Sue Ann is excited by the "adventure" and entreats Dennis to run away with her to Mexico. First, however, they have to get rid of her disapproving mother. Dennis realizes that Sue Ann is a sociopath, but knows that the police will take her word over his, so he takes the blame for their crimes. Sue Ann, meanwhile, betrays him without a second thought, sending him to prison for life. Dennis refuses to tell his skeptical parole officer the truth, but asks him to "see what Sue Ann is up to" in hopes she will be exposed for what she really is. The film ends with Sue Ann meeting a young man and lamenting to him that the people who took her in after her mother's death won't let her stay out late; it is implied that she will use and destroy him just as she did Dennis. But Dennis' parole officer is indeed watching as she departs with her latest victim.