In the peaceful seaside town of Broadgate, an impossible crime occurs. The operator of the cliff railway locks the empty carriage one evening; when he returns to work next morning, a dead body is locked inside - a man who has been stabbed in the back.Jimmy London, a newspaper reporter, is first on the scene. He is quick on the trail for clues - and agrees to pool his knowledge with Inspector Shelley of Scotland Yard, who is holidaying in the area.