Has Anyone Seen This Girl?

A very short novel told in a diary format. New girl on way to boarding school, desperate to make friends, meets girl in same uniform on train, befriends her, finds she is school outcast because of strange behaviour, dilemma - should she stay true to her friend or ditch her to be part of the larger group? There's no easy answer to this problem just as there are no easy answers about any of the girls in this book including Caroline, the narrator, who admits her own failings and her own responsibility for Rachel's eventual disappearance. Much to think about on the themes of friendship, loyalty and peer group pressure, but what a price for 86 pages!