In France the husband of a purity league leader runs a shady nightclub.

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...

A British crime film directed by Norman Lee