Ed Harwood, a wisecracking private investigator from New York, discovers a crime at a hotel in Nice during a carnival. The unraveling of the mystery which lies behind will lead him and Caryl Fenton, a female insurance agent, who will become his companion, first to Paris, then to London, later through the English countryside and finally to Southampton, in search of a criminal train wrecker.
A businessman's daughter runs away from an arranged marriage, only to find herself penniless and suspected of theft after she becomes the victim of a bag thief in the train. When she refuses to tell him who she really is, her accuser decides to take her home where he can keep an eye on her until 12 o'clock the next day, the time at which she has calculated that it will be safe to tell the truth! But when his fiancée arrives unexpectedly and then his 'guest' is mistaken for her, it all gets rather embarrassing...
London has become enthralled by the antics of the contemporary Robin Hood, but when a band of bad guys start framing him for their misdeeds, the hero has to catch the criminals and clear his name.
