Victor Rait has developed a new method for converting opium to heroin and he and his partner Arnold Stegler hope to make a handsome profit. When Rait kills a Chicago policeman, who was actually on loan and working for Eliot Ness, he realizes that they have to clear out of their current location. Just as they are leaving Ness and his men arrives and Rait pretends to be an innocent bystander and witness to the shooting.