Col. Henry, aka 'X' hires Jane to be his secretary and tells her to meet him at the supposedly haunted Ghastly Grange.

Jane and Fritz have scared off an intruder during the night. The next morning they meet Lola Pagola, Professor Donner's assistant. However, there is no sign of the professor at the station.

Jane finds a secret message hidden in a French lipstick. But when she puts it on, Georgie Porgie identifies her as the spy he's been looking for.

Jane finds a smugglers cave filled with weapons and uniforms, as well as Tombs the butler all tied up. Now it is up to the two of them to stop a German invasion.

Jane, the Colonel, his wife and Major Dunlighty are all tied up in the Ghastly Grange cellar and a German U-Boat is about drop it's men on the British shores.