Sue Ann, a highschool cheerleader, unknowingly manages to grab the desire of protagonist Dennis Pitt: a mentally unstable man recently released and under probation. Dennis, who has had issues separating fantasy from reality, falsely tells the young blonde that he is an undercover CIA agent and attempts to incorporate her into his "missions" so that he can spend time with her. Sue Ann believes him and willingly obliges.
One night, while sneaking around the Sausenfield Chemical Company - Dennis's current place of employment - he is spotted by Sam, the night watchman. Before her lover can react, Sue Ann knocks Sam out with a wrench. She then drags him into the water and, quite gleefully, drowns him; stating that his corpse will be covered up the following morning when the metal cute collapses.
After learning that her mother receives information regarding what happened, Sue Ann decides that she wants Dennis to murder her, too, using the pistol she pilfered from Sam's corpse. When he refuses, Sue Ann gladly does the evil deed herself. After convincing Dennis to go get rid of the body, she then frames him for the murder.
Back in prison, Dennis is at peace with the circumstances; stating that the best thing he could have done is nothing, for poison - when left alone - only becomes more and more apparent until the blindest man can see it. Sure enough, one year later, Sue Ann is already working to convince a new boy in town to murder her new foster parents. However, Dennis's parole officer - believing the protagonist's innocence - has committed himself to watching her like a hawk. It is never revealed, however, if Sue Ann was ever arrested for her crimes.