Miss Harcourt, St Monica's Headmistress, is forced to be away from School for a term through illness. Consequently a temporary Head has to be found. Miss Harcourt is unable to interview anyone, so she write to an old friend-Miss Pennington-to ask her to deputise for her, and is glad to hear that this can be arranged. Miss Pennington arrives at St Monica's, and from the very first is up against the girls. The School Games Captain resigns her post, some of the younger girls form a society to try to reform Her Nibs-as they call their new Head-even the Staff do not agree with her arbitrary methods. Only the Head Girl is loyal throughout. She discovers elements of mystery surrounding Miss Pennington, but confides in no one. The mystery deepens and grows most exciting before it is finally solved in a dramatic way. The original naughtiness of the Black Quintet, an unusual botany ramble, and a thrilling Sports Day make this story of an extraordinary term fresh and fascinating reading.