For Ness, a master bank robber proves a worthy opponent. But robbing banks is not a federal offense, so Ness must get him on another charge.

Although unsuccessful in their first attempt to assassinate Chicago's Mayor, Anton J. Cermak, the Capone mob under the command of Frank Nitti and several other of the imprisoned mobster's lieutenants, have not given up. This time they hire a professional, Fred 'Caddy' Croner, an expert at using a long rifle with a scope who carries his weapon in a golf club bag.