The Mystery of the Spiteful Letters

Someone is sending spiteful letters. Gladys and Mrs Moon are terribly upset. There are lots of suspects—it could be gossipy Miss Tittle or Old Nosey, a very curious man. The Five Find-Outers and Dog will find the culprit!

The fourth mystery is a little disappointing in the end. It starts off well, with Fatty disguising himself as a red-headed telegragh boy who "accidentally" lets his bike fall on Mr Goon's shins while he delivers a telegram to the others saying that Fatty has gone to solve a mystery in Tippylooloo (somewhere in China). The telegraph boy is very apologetic and polite, and Mr Goon actually likes him: "There's a boy that's civil and respectful to the law," he says as the boy cycles away. Later in the book Fatty dons the same red wig and pretends he's a butcher boy, and later still a parcel delivery boy.