When Bertie Wooster expresses the desire to go to Deauville in search of adventure and romance, his "gentleman's gentleman" Jeeves gives notice that he will leave the next morning because Bertie's earlier exploits endangered the placid Jeeves. That night, a mysterious woman followed by two men takes refuge in the Wooster home in London to Bertie's delight. The next day, annoyed that Jeeves let the woman leave during the night, Bertie, having learned from a telegram that she was expected at Mooring Manor Hotel, convinces Jeeves that they should go there. On the road, Jeeves and Bertie pick up Drowsy, a stranded black American saxophonist. After a furious chase, Tom Brock and Jack Stone, the men who followed the woman, identify themselves to Jeeves and Bertie as Scotland Yard agents and say that the woman stole important papers. At the hotel, which was once the manor of a viscount, the woman, Marjorie Lowman, is surprised when the clerk relates that Edward McDermott, whom she telephoned there the previous evening, has never been there. Elliott Manville, who attacked McDermott and took his half of a blueprint, tells her that he will help. Bertie tries to convince Marjorie to give up to the police and to marry him, while Jeeves teaches Drowsy to play "The March of the Hussars." Carried away by the finale, the two crash through a trap door into the cellar. Marjorie follows Brock and Stone through a secret compartment leading to the cellar, where she pulls a gun on them and Manville. Bertie, who has followed her, takes her gun and gives it to Manville before he realizes that they are not policemen. After they get Marjorie's half of the blueprint, Bertie switches out the lights, grabs the plans and rushes out with Marjorie. Jeeves, formerly an amateur fighter, knocks out their pursuers and fights the hotel staff with medieval weapons which he finds lodged in the cellar. After McDermott, who is Marjorie's cousin, arrives with the police, Marjorie explains that Manville wanted to sell the plans for McDermott's invention to a foreign government. Bertie, who had been chained to the wall along with the crooks by Drowsy after Jeeves mistakenly clunked his helmeted head, proposes to Marjorie, who accepts. Jeeves gives notice again and begins to file off the chains.