In Chicago, Richie 'Triggerman' Trivoli has come from New York to fulfill a contract at the closing of the 1934 World's Fair; he is encroaching on the territory of the Capone organization, and he must also outmaneuver FBI agents Mel Purvis and William Ashley, who have set their sights on him. But Trivoli is the best there is, and no-one has ever stopped him before.