Edgar is unhappily married to rich Clare. He plots with his mistress Stella to kill Clare, as she refuses to divorce him and gives him little money. However, it is Edgar who is found murdered, and Clare has to stand trial to prove her innocence.

During New Year's Eve, a young model spends the day searching for her grandmother, who has suspiciously gone missing.

Someone knocked out a man and left him for dead during a fishing trip in Portugal. That someone is either his fetching wife, or two business partners, all sporting guilty faces after his unexpected return. Two more murders and a frame-up befall the quartet before an inspector closes the case.

A gang of four would-be robbers plans to steal a fortune in currency hidden aboard the "Flying Scotsman" in a railroad stateroom by cutting through the wall of the adjacent stateroom, but find themselves up against numerous unexpected drawbacks, including interference by their fellow passengers.