With the end of Prohibition, gangsters have now focused on the drug trade. A New York-based syndicate known as the Big Six, long established in the illegal drug business, visit drug distributor Louis 'The Bear' Madikoff in Chicago who has had his recent shipments to Lucky Luciano in New York picked off by Eliot Ness and his agents. Madikoff is convinced that fellow Chicago drug dealer Mike Pavanos is responsible for feeding Ness with information so he sets out to even the score. It turns out however that Madikoff's son Danny is dating Pavano's daughter Francie. 

The mobsters are fighting among themselves for greater control of the beer market and Frank Nitti thinks he has the perfect solution. He is smuggling German brew masters into the United States and as a result, is making a far superior product than his competitors. This doesn't sit well with the New York mob, particularly Joe Kulic who decides to do something about it. He hires enforcer Karl Hansa, a bit of a madman, to infiltrate Nitti's operation and shut it down.