After a falling-out concerning Bertie's relentless playing of the banjolele, Jeeves leaves his master's service and finds work with Bertie's old friend, Lord "Chuffy" Chuffnell. Bertie travels to one of Chuffy's cottages in Somersetshire to continue practising his banjolele-playing without complaints from his neighbours.
Chuffy, whose high rank is matched only by his low financial status, is hoping to sell his dilapidated family manor to the millionaire J. Washburn Stoker, who in turn plans to rent out the property to the famous "nerve specialist" (or, as Bertie prefers, "loonie doctor") Sir Roderick Glossop, who intends to marry Chuffy's Aunt Myrtle. Chuffy has also fallen in love with Mr. Stoker's daughter, Pauline, a former fiancée of Bertie, but feels unable to propose to her until his finances have improved enough to be able to keep her in the style to which she's accustomed.
Upon being informed of the situation, Bertie hatches a plan to make Chuffy propose: he is going to kiss Pauline in the presence of his old friend, in the hope that Chuffy will be spurred on to propose himself. When he puts his plan into action, however, he is seen, not by Chuffy, but by J. Washburn Stoker, who is convinced that Pauline and Bertie are still in love, and that he must exercise ceaseless vigilance to prevent them from getting engaged again. Even worse, from Bertie’s perspective, all hopes of marriage between Chuffy and Pauline seem dashed after a fight between Mr. Stoker’s young son Dwight and Chuffy’s cousin Seabury leads to a more general row between the Chuffnells and the Stokers. Mr. Stoker returns to the yacht in which he and his family are staying, keeping Pauline a virtual prisoner on board to stop her eloping with Bertie.
Chuffy writes a love letter to Pauline which Jeeves is able to smuggle aboard the yacht by pretending to enter Mr. Stoker's employ; Pauline is so moved that she swims ashore, where she goes to stay in Bertie's house until she can visit Chuffnell Hall in the morning. Bertie chivalrously lets her sleep in his bed whilst he tries to sleep in the garage. Unfortunately, he is seen by Police Sergeant Voules, who informs Lord Chuffnell of Bertie's strange behaviour. Chuffy, thinking that Bertie is intoxicated, takes him back up to his bedroom. Upon discovering Pauline there, he leaps to the conclusion that she and Bertie have resumed their romantic relationship. A heated row breaks out, which ends with Pauline declaring that she never wants to see Chuffy again. The two lovers return to their respective homes. Bertie is then disturbed by Mr. Stoker, who has found Pauline missing, and jumped to the conclusion that she has run off with Bertie. Upon searching Bertie's cottage and not finding her, however, he apologises and leaves.
The next day, Bertie gets a message from Mr. Stoker, requesting his presence on board the yacht for his son's birthday party. Despite his misgivings, Bertie goes, only to be locked in one of the staterooms by Mr. Stoker, who informs Bertie that he has found out about Pauline's visit to him the previous night. He plans to force Bertie and Pauline to marry. Jeeves, however, is able to help Bertie escape: Mr. Stoker has hired some negro minstrels for his son's party, and Bertie is able to disguise himself with boot polish and get ashore with them. Bertie returns to his cottage, where he encounters his new valet, Brinkley, in a state of considerable drunkenness. Mistaking Bertie (who is still in blackface) for the Devil, Brinkley attacks his employer with a carving knife, before accidentally setting the cottage on fire. In the ensuing conflagration, Bertie's banjolele is destroyed.
Hoping to find some butter to help remove the boot polish from his face, Bertie goes to Chuffnell Hall; Chuffy, however, thinking that Pauline is in love with Bertie, tells him that he ought to marry her, and refuses to (as he sees it) help Bertie in wriggling out of his obligations. Bertie then meets Jeeves, who has returned to Chuffy's employ to avoid Mr. Stoker's wrath when he finds out about the part Jeeves played in helping Bertie escape. Jeeves informs Bertie that a disagreement has broken out between Sir Roderick Glossop and the Chuffnells. Sir Roderick had blacked up and tried to entertain Master Seabury; Seabury being unappreciative, however, Sir Roderick had subjected the boy to what Jeeves tactfully calls "severe castigation", and left the Hall. Jeeves moreover informs Bertie that Seabury has stolen all the butter in the Hall to use in a practical joke on Sir Roderick, but that Bertie can sleep in the Dower House, where Jeeves will bring him some the next day.
The Dower House is rendered uninhabitable, however, by the presence of Brinkley. While waiting outside and wondering what to do, he meets Sir Roderick Glossop, towards whom he feels considerably friendlier since learning of the argument with Seabury. Sir Roderick goes to Bertie's garage to find petrol, which he says is as good as butter for removing blackface; Bertie, worried about meeting Sergeant Voules again, remains in the Hall's grounds.
The next day, Bertie meets with Jeeves in Chuffy's office. Their conversation is cut short, however, when Mr. Stoker arrives, hoping that Chuffy might be able to tell him where Bertie is. Meeting Jeeves, whom he has not forgiven for freeing Bertie, Mr. Stoker threatens to break the valet's neck; Jeeves is able to disarm him, though, by claiming that he only helped his former master to protect Mr. Stoker from a charge of kidnapping, and tells him that Bertie has gone to the Dower House. Pauline Stoker arrives next, and tells Jeeves that she once again wishes to marry Chuffy. Jeeves leaves to search for Sir Roderick, and Bertie reveals himself to Pauline in the hope that she’ll be able to get him some breakfast. Frightened at Bertie's sudden appearance, Pauline emits a piercing shriek, bringing Chuffy running to her. Their past animosities forgotten, the pair seem completely reconciled.
Mr. Stoker returns, having had a run-in with Brinkley in the Dower House. Jeeves also comes back, bearing a cable saying that some of Stoker's relatives are contesting a will, which resulted in Mr. Stoker inheriting some fifty million dollars from his Uncle George, on the grounds that the deceased was insane. Stoker seems unconcerned, saying that Sir Roderick will testify for him that his uncle was in good mental health. It turns out, however, that Sir Roderick has been arrested trying to break into Bertie's garage, and it seems unlikely that the nerve specialist's testimony will carry much weight if he is imprisoned. Jeeves suggests that Bertie switch places with Sir Roderick, as he could hardly be charged with breaking into his own garage. The plan succeeds; Chuffy's financial problems are resolved when Stoker agrees to buy the Hall from him; he and Pauline are to be wed; and Jeeves, who has a policy of never working in the household of a married gentleman, returns to Bertie's employ.