A World War I veteran runs one of the city's most vicious extortion rackets, tasked to protect Chicago's butchers from the mob. But a double-cross by one of his own gives Ness an opening to trap the thug.

Eliot Ness knows that John "The Cropper" Cropsie killed Belle Alpine's husband and that she witnessed it but for reasons of her own, she won't identify him. Cropsie is a small-time hood who wants to get into the big-time and gets a job loan-sharking for Julie Flack. One of his marks tells him that a local company has manufactured 50,000 gallons of industrial alcohol. He manages to steal the precious liquid and tries to sell it to Flack. Ness is onto him quickly and Cropsie has made a serious error in including Belle Alpine's brother-in-law Murray in his plans.