"Willoughby Chase" is a children's novel written by Joan Aiken. Set in an alternate version of 1832 England, it follows the adventures of two cousins, Bonnie and Sylvia, who face challenges after the arrival of a sinister governess. The story explores themes of bravery, friendship, and the struggle against evil. The novel is known for its rich, atmospheric writing and engaging plot. It features elements of fantasy and adventure, as the girls work together to save their home, Willoughby Chase, from the clutches of the villainous Miss Slighcarp. The book is part of a larger series that continues their adventures.