The three men involved in the robbery are Harper, Chapman, and Dill, each with their own motivations for participating in the heist. Harper is a former mining engineer who lost his job due to alcoholism and needs money to support his family. Chapman is a Korean War veteran who wants to prove he is still capable of taking risks and earning money. Dill is a sadistic criminal who enjoys the thrill of the robbery and inflicting harm on others.
The town of Bradenville is depicted as a peaceful and idyllic community, with townspeople going about their daily lives and not suspecting any danger. However, as the three men prepare for the heist, tensions rise among them, and they begin to argue and fight. Meanwhile, the townspeople have their own secrets and conflicts, including an unhappily married banker, a promiscuous librarian, and a teenage boy struggling to find his place in the world.
On the day of the robbery, the men enter the bank with guns and explosives, but things quickly spiral out of control. The townspeople attempt to fight back, and a series of violent and chaotic events unfold, including a car chase, a shootout, and a brutal fight in a factory. Several characters are injured or killed, including innocent bystanders caught in the crossfire.
Ultimately, the surviving robbers are apprehended, and the town is left to pick up the pieces and heal from the traumatic events. The film is notable for its use of CinemaScope and Technicolor, as well as its focus on character development and interweaving storylines.