Joseph December is a legitimate businessman and the scion of a wealthy family who own the Great Lakes Pacific railroad which, by all accounts, is on its last legs. With Eliot Ness receiving hot tips and managing to intercept liquor being smuggled in from Canada, Al Capone enforcer Pete 'The Persuader' Kalmiski and his underling Allan Sitkin approach December to make a deal. In return for letting them use his railway, December get to keep 20% of the proceeds. The death of a railway track worker however puts Ness and the Untouchables onto the scheme. When a side deal on shares with Sitkin goes bad and he commits suicide, December gets hold of information that he hopes he can use against Kalmiski. December's right hand man, Henry Grunther, is appalled at what is happening to the company and seeks Ness' assistance.