Small-time Boston crook Tony Pino (Peter Falk) tries to make a name for himself. He and his five associates pull off a robbery whenever they can. Tony and his gang easily rob over $100,000 in cash from a Brink's armored car, after which Tony disguises himself as a sparkplug salesman to get an inside look at Brink's large and so-called "impregnable fortress" headquarters in the city's North End, Boston, a company renowned for unbreachable security as a private "bank" throughout the East Coast.