Nick Robey (John Garfield) is a dim-witted thug who lives with his mother and scrapes by on petty crime. He and his slick accomplice, Al (Norman Lloyd), plot a big-time payroll robbery, but their plan goes horribly awry when they're discovered by a police officer and Al is shot. Nick shoots back, hitting the officer and running for safety. While seeking cover, Nick meets Peggy Dobbs (Shelley Winters), a lonely young girl. They return to Peggy's house, where Nick holds her family hostage.