Plot summary

Young Treasury Agent Eliot Ness arrives in Chicago determined to bring down Al Capone. However, this proves difficult due to Capone having control of Chicago police forces and Jim Malone being one of their more honorable patrolmen; Ness approaches Malone for help but instead warns him that any attempt against Capone means going into battle against Al. Malone advises Ness against going against Al and thus warns him against it as doing so would mean war against Capone himself.