Claustrophobic train-set comedy-thriller (produced by H.G. Wells son) with an ace reporter coming up against crooks intent on stealing a gold shipment on the Scotland to London express. A scatterbrained scientist, a gun-toting dame with revenge on her mind and a pair of eccentric spinster crime novelists – who steal the film – round out the motley band of passengers who cross the path of our intrepid hero as he tries to get his big scoop.