Clarence, 9th Earl of Emsworth, is forced to play host to his younger son Freddie, while two of his nieces, Prudence Garland and Veronica Wedge are romantically entangled with, respectively, Gally's godson Bill Lister and American millionaire Tipton Plimsoll.

Complications ensue when the near-alcoholic Tipton thinks that Bill's gorilla-like face is an apparition brought about by too much drink; Lister, purporting to be a notable artist named Landseer, is commissioned to paint the portrait of Emsworth's prize pig, the Empress of Blandings; and the valuable necklace of Freddie's wife, Aggie, goes missing.

Lord Emsworth is aghast to learn that his younger son Freddie is back in England from America, sent over to push "Donaldson's Dog-Joy" to the English dog-owning public.

At Blandings, Colonel and Lady Hermione Wedge are excited by the prospect of their beautiful daughter Veronica meeting such a wealthy man, even more so when the two hit it off immediately.

Lister's style fails to please Lord Emsworth, and the two fall out, but Freddie, at Gally's suggestion, smuggles him back into the castle disguised as a false-bearded gardener, having paid off Angus McAllister.

Lister soon ruins things, however, when after scaring Plimsoll once more and terrifying Veronica, he mistakes her mother for the cook and tries to bribe her to pass a note to Prudence.

Hermione approaches, and Gally successfully fools her into thinking he still holds the necklace; Emsworth, hearing his son is in danger of getting divorced and returning home for good, hurriedly pays for Lister's business.