Freddie Threepwood and his uncle are in difficulties. Freddie wants a thousand pounds to start a bookmaker's business and to marry Eve, while his uncle wants to raise three thousand pounds, unbeknown to his wife, to help a runaway daughter. Freddie persuades his uncle to steal his wife's necklace and sees Psmith's advertisement in a daily paper.

Freddie enlists the services of Psmith to steal the necklace. There are plots and counterplots. Psmith is not successful in stealing the necklace but succeeds in stealing the affections of Eve.