Bill Bergson, Master Detective (novel)

Bill Bergson, Master Detective (original Swedish title Mästerdetektiven Blomkvist) is a children's novel by Astrid Lindgren. It is the first in the series about the Swedish boy detective, in English translation named Bill Bergson (Swedish name: Kalle Blomkvist).

Plot summary
Bill Bergson investigates his friend's mysterious cousin, who is behaving suspiciously, and solves the mystery of a jewel robbery.

Bill and five of his friends also play a mock war game, with the White Roses and the Red Roses vying for possession of an unusual stone.

Film
There is a film based on the book, Bill Bergson, Master Detective, produced in 1947.