Den vita stenen ("The White Stone") is a 1964 Swedish children's book written by Gunnel Linde.
People say bad things about Mrs Pettersson because she is useless and lazy as she just plays piano.
[1] One summer day, a boy called Hampus comes to the village together with his stepparents, his uncle who is a poor shoemaker and his wife, and their 6 children.
The two children, who are alienated, start their own fraternity and call themselves "Fideli" (Fia) and "Farornas konung" ("King of the Dangers", Hampus).
[1] In 1973 a TV series with 13 parts, directed by Göran Graffman, based on the book, was produced.