The infamous 1920's St. Valentine's Day Massacre involved a fight between gangsters. In the complicated underworld of Al Capone's Chicago, Jack McGurn is really Vincent Gebardi, a coldly efficient killer. Louise May Rolfe is his wife. As Jack/Vincent was being hunted as the perpetrator of the killings on St. Valentine's Day, his life was examined in minute detail by the press, and the couple's excesses and extremes define the Prohibition era in America.