A working knowledge of Morse code and the foresight to pick a train driver for a sweetheart come in handy in this ‘race to the rescue’ thriller. When the wealthy Mr Harvey has to go away on a train journey, a couple of sharp-eyed crooks take the opportunity to burgle his home. Only the live-in maid stands between them and Harvey’s safe. Can our plucky heroine save the day?

• Hepworth