When gangsters invade and shoot up a speakeasy on the outskirts of Chicago, Ness thinks Frank Nitti may be trying to get rid of some of his competition. When one of Nitti's joints is bombed soon after, the authorities are worried that a massive gang war may erupt. The problem for Nitti is that the out-of-town clubs are getting quality booze smuggled in from Canada and its drawing away his well-heeled customers.

In New York on a case, Eliot Ness learns that mobster Joe Kulak is out to get control of the racing wire. The wire provides horse racing results from tracks across the country to betting parlors and bookies. The mob is out to get control of Michael Barrigan's wire service and they've killed Barrigan's two partners to put pressure on him. With information that Gregory Pindar will be running the mob's wire service, Ness travels to San Francisco undercover posing as hoodlum Whitey Steele to see if he can infiltrate the new operation.