This exciting caper outing is loosely based on the famous robbery of Brinks in Boston that netted the crooks $2.5 million. The story covers the six years small-time hood Jerry Florea (Tony Curtis) spent planning the heist. The story begins with the events that led a young Florea (played by Sal Mineo) to become a crook. Hoping to save him from a life of crime, a kindly policeman and his wife take him under their wing. Though he appreciates their kindness, Florea seems destined to become a criminal. As a young man, he begins pretending to reform and even gets a job at Brinks. The loving couple have no clue that it is only a ruse and that he is preparing to rob the establishment. It is only after he and his gang pull-off the job that Florea reconsiders his actions and then makes a daring attempt to make amends.