With the imprisonment of Al Capone for tax evasion, Frank Nitti has taken over the operation of the organization but that isn't stopping others from trying to muscle their way in. Arnie Seeger in particular thinks he has the opportunity to create a national crime syndicate and partners with St. Louis mobster Joe Kulak to make it happen. They plan on inviting key mobsters from across the country to a conference in Chicago. Into this mix comes a recently released small-time criminal, Maxie Schram. His wife Roxie now lives with Seeger and Maxie tries to hit her up for money. Down and out, he has no choice but to turn to Eliot Ness as an informant after his wife refuses to help him. It is Maxie that puts Ness and his men on Seeger's trail. When Kulak kills a policeman who had wiretapped the site of the syndicate conference, theirs is now a murder investigation as well.
—garykmcd