Bertram Wilberforce "Bertie" Wooster returns home with a hangover when a valet named Jeeves rings the doorbell. He fixes Bertie his special hangover cure, and when it proves effective Jeeves is immediately engaged. Bertie has lunch with his aunt Agatha - "the nephew crusher" - at which she announces he must marry, and that the suitable candidate is Honoria Glossop. Bertie has no intention of marrying anyone, and discovers that Bingo Little is in love with Honoria. He hatches a brilliant plan to get Honoria out of his hands and in to Bingo's...
Bertie's current love interest sets him up by giving both him and his rival Barmy the same idea for a practical joke, then gives away the terrier belonging to his Aunt Agatha which he is dog-sitting. Then Bertie is told to break up his friend Tuppy's interest in an opera singer.
When Bertie is instructed by Aunt Agatha to break up his uncle's engagement to a young waitress, he arranges a luncheon for his uncle and the girl's aunt, a common, gaudy woman -- who turns out to be the uncle's long-lost barmaid love. To escape Aunt Agatha's wrath, Bertie and Jeeves travel to the country residence of a friend to enjoy the local fair, where the bookie manages to handicap all the entrants on which Bertie and his friends bet.
Bertie tries to play Cupid without Jeeves' help. His friend Gussie is in love with Madeline, who happens to be staying at Bertie's Aunt Dahlia's house, so Bertie arranges for him to visit. Meanwhile, Aunt Dahlia is desperate to coax 500 pounds out of her husband for her failing magazine, and Tuppy's engagement to Angela Travers is off. Bertie's recommendation to both of them is the same: don't eat the wonderful food of Aunt Dahlia's chef Anatole at dinner, to show how lovelorn and miserable they are. But they become much more miserable when Anatole gives notice.
Bertie is offended because Jeeves was dispatched to convince Anatole to return to Brinkley Court, so he continues to attempt to reunite Tuppy and Angela and bring Gussie and Madeline together; consequently, Gussie and Angela wind up engaged, and Madeline expects Bertie himself to marry her.