Jeeves has established his justifiable reputation as an invaluable solver of problems of all kinds. However, when Gussie Fink-Nottle follows Jeeve's advice to attend a fancy dressed party rigged out as Mephistopheles, he comes badly unstuck. Could it be that Jeeves has lost his grip? Bertie decides that Jeeves is not the only onion in the hash and he embarks on a plan that will, he believes, make Madeline become engaged to Gussie, that will re-unite cousin Angela with Tuppy and will make Uncle Tom cough up some cash for Aunt Dahlia. However, as you may expect, Bertie's schemes have a knack of going awry and, before long, everything and everyone is in a state of confusion.