A confused man (Tom Conway) with a gash on his head stumbles into the taxi of cabbie Patty Mitchell (Ann Rutherford). He says that he can't recall his own name, any facts about his life or even what he was doing before he got in the cab. The sympathetic Patty decides to help him try to reassemble the pieces of his past, but, as they scour the city for clues, they learn the cops are investigating a murder that took place just prior to the man's blackout -- and he fits the killer's description.