B-movie ghost story starring Hazel Court and Dermot Walsh as a young couple who decide to buy a luxury steamboat for a romantic getaway. They think that they've found the perfect boat, and scoff at warnings that it's haunted. However, despite their initial incredulity they are gradually convinced that there is something strange going on in their new love-nest, and they decide to bring in a paranormal expert, Professor Mansel Martineau (John Robinson) to investigate. A horrifying secret about the boat's previous owners is eventually revealed...

Will Hay plays Professor Davis, the intrepid head of a correspondence college, in this wartime comedy. Davis gets wind of the fact that a Nazi spy has infiltrated an economic delegation with the intent of undermining attempts to reach a trade agreement between Great Britain and certain South American countries. The effort to expose the dastardly fellow sees Hay adopt various disguises in a steady onslaught of mistaken-identity comedy.