Despite police warnings, an engineer takes on a teen gang.

Late one evening space scientist Walt Sherill is attacked and, for no apparent reason, brutally beaten by a gang of well-dressed teenagers. Brooding over his injuries, he becomes impatient with Detective Sergeant Koleski's failure to get immediate results and he decides to take the law into his own hands. Obsessed by his thirst for vengeance, he loses his job, interferes with Koleski's work, and antagonizes innocent citizens. His coercive attempts to see justice done eventually cause one of the gang members to panic and commit suicide. Chuck Landry, the wealthy psychopathic gang leader, terrorizes Walt's wife, Tracey, in revenge. Following the death of a private detective he hired to track down the boys, Walt finally catches up with Chuck at his family's home. He almost kills the boy before realizing that he is sinking to the youth's own vicious level. Coming to his senses at last, he turns Chuck over to Koleski.