The Very Wicked Headmistress by Margaret Mahy
The wicked Miss Taffeta, notorious cheater and blackmailer, former trapeze artist and the human cannonball, opens a select school for rich young ladies. Everything seems perfectly normal until certain happenings at the school make the girls suspicious. Is Miss Taffeta a mistress of disguise as well? Huge fun from the endlessly original pen of Margaret Mahy with witty illustrations from Margaret Chamberlain.