The Widow from Chicago

Vice lord Dominic has brought Swifty Dorgan east to do a job for him. When Swifty appears to have died falling from a train, detective Henderson impersonates him hoping to get into the mob. When he's killed his sister Polly poses as Swifty's widow and gets a singing job at Dominic's nightclub. Then the real Swifty shows up. (official distributor synopsis)