At the corner of Ocean View and Arch Street, a disoriented man stumbles out of the fog and into the street, where he is almost run over by cab driver Patty Mitchell. The man is suffering from amnesia and the only clues to his identity are a hatband embossed with initials "R.D.," two ticket stubs from the Imperial Theatre and a matchbook from the Blue Room at the Regency Hotel. Patty drives the man to a police station for help, but when they see a newspaper story reporting the murder of producer Robert Dilling on Ocean View by a man wearing a pin-striped suit and fitting the man's description, Patty decides to help her amnesiac passenger recover his memory and prove his innocence.