'A retired policeman is telling his grandchildren the "real life" horror story of "Dicky" Dingle. "Dicky" was the groundsman at a small bush school, none too bright and lamed by polio - a sitting duck for some of the nastier children, who make his life a misery. Unbeknown to the children, "Dicky" plans a horrible revenge on his tormentors.'
Source: Bookseller's website