This is one of Wodehouse's stand-alones. Starting out in Claines Hall, where Mrs. Chavender has ham for breakfast, setting off all sorts of consequences.
She doesn't like it. And when Sally Fairmile, the poor relation who procured it, tells her where she got it, Mrs. Chavender realizes that it is a Paramount ham, which J. B. Duff is so fascinated with producing and selling that she broke off her engagement to him on hearing about them once too often. She is going to tell him what she thinks of them, Lord Holbeton, who had just gotten engaged to Sally, is horrified because Duff is his trustee and he has to get some money out of him. Sally herself engages to go -- she is, after all, going anyway to get a new valet for Mr. Stephoe, the master of the house, who has a distressing tendency to not dress as she wishes, and whose valets find it impossible.
At J. B. Duff's office, he is faced with an artist who does posters -- Joss Weatherby, a man with a great deal of impudence and self-confidence, which is how he manages to face down Mr. Duff. When Mrs. Chavender arrives, Mr. Duff avoids her but has the brilliant notion of using an imperious portrait of her (painted by Weatherby) as a poster. And then Sally arrives, Joss falls in love at first sight, and when Mr. Duff fires him, he offers himself up for the job of valet.
Oddly enough, Mrs. Steptoe, who owns the portrait, refuses to sell. Thus setting Mr. Duff, too, to arrive at Claines Hall, where all these characters continue the wacky incidents and fantastical and whimsical plots of a Wodehouse novel. Involving love triangles, reuniting lovers, rival burglaries, rain, coal cellars, Weatherby's astounding ability to get Mr. Steptoe to dress properly, the song of a non-existent nightingale, a fake mustache, jealousy, and a tea room.
All looped together with the kind of adroitness that only Wodehouse could really pull off.