Summer 1933, Chicago. The mobsters were branching out from liquor, going into the numbers racket, call girls, gambling and dope. One of the most successful gangsters is "Big" Jim Harrington; right now he and his gang are in back of Benny Hoff's Blue Poodle nightclub, and they smash a truckload of liquor. Harrington tells Hoff, from now on, he will only buy booze from him-- and Harrington demands 75% ownership. When Hoff balks, one of Harrington's boys, Loxie the Torch, intimidates Hoff. Loxie takes out a whiskey hip flask, but it's not filled with whiskey. Loxie goes, "Alright, now, smell it," as he pours the gasoline on the terrified Hoff, "light a match and >fshhh!!<" and he holds the lighted match up to him. Hoff doesn't want his club to be torched, too; the club becomes Jim Harrington's Blue Poodle. Harrington was out to get ownership of all the speakeasies and nightclubs in Chicago, and flood the town with his rotgut-- 1,000 gallons a day. The violence was a matter for the police; the booze was a federal matter. And so Eliot Ness meets with Hoff, but Hoff doesn't want to talk about it. Hoff also owns another small club on the side, a German beer garden called the Double Eagle. Hoff is manager and best friend of a stand-up comedian named Johnny Paycheck, who is working there this week, and his jokes are strictly from hunger. Paycheck regales the audience, "We were so poor, one day my mom said to the landlord, 'What about the floor?' and he said, 'What about it?' and my mom said, 'We want one'." You get the idea. Harrington is in the audience with his moll Renee Sullivan, and figuring that Paycheck's rotten jokes are no worse than his rotgut, he offers Paycheck a job in one of his downtown speaks, the Blue Poodle. Harrington now has his sights set on taking over the swankiest nightclub in town, Schlessinger's Mohawk club. Eliot Ness warns the owner about Harrington's plan to take over. 6 weeks later, Johnny Paycheck has picked up some better jokes (thank heavens) and is a big hit at the club; he's also picked up Renee as his main squeeze. Renee works as a dancer in the floorshow. Later, Hoff packs up and wants to move to New York; Johnny tells him he and Renee will go with him. Loxie the Torch meets up with Schlessinger; "Have a drink on me," Loxie tells him-- gasoline, and then the lighted match. One night, Harrington is throwing a private party, ostensibly in Johnny's honor: he tells Johnny that he's opening at his new club, the Mohawk. At exactly the same time, Hoff-- knowing that Paycheck will never be free of Harrington-- goes to a phone booth and tells Ness that Harrington has a big still downtown, by a mattress factory, then the booze is pumped via sewer pipes to a bottling company. Ness tells Hoff that he wants to put him into protective custody; Hoff says his famous last words, "You don't have to worry about me." Loxie the Torch is driving a car, and flattens Hoff between a brick wall and his grill. In one of the rare times he's wrong, Ness figures Paycheck had Hoff killed, because he was holding him back from the big time; Ness shakes down Paycheck. In the wee hours of the morning, Ness and his men raid Harrington's still, in an abandoned power plant (with a smokestack to emit fumes) by the mattress factory. In the shootout, Rossi gets winged in the left shoulder. Meanwhile, Johnny gets the straight dope from Renee-- she's not his girl, she's only with him because Big Jim told her to; and the party in his honor was just a cover, to establish an alibi for Loxie the Torch, who was rubbing out Schlessinger at the time. Johnny tries to grab a train to New York. He's intercepted by Loxie. Back at the club, at a private meet, Harrington makes Johnny do his new act-- but he's such an emotional wreck that he's all washed up. Harrington tells Loxie to torch him. Just then, Ness and his men bust in; he's finally got the goods on Harrington, since he raided his still. Gunfire, and Ness shoots Loxie. Harrington is arrested by Ness who has to pull Johnny off of him. Johnny had finally tried to do the right thing after the death of his friend Benny but by then it was a little too late.