Orphan, Monster, Spy by Matt Killeen

Shortlisted for the Costa Children's Book Award and the Branford Boase AwardNominated for the CILIP Carnegie Medal A teenage spy. A Nazi boarding school. The performance of a lifetime. Sarah has played many roles - but now she faces her most challenging of all. Because there's only one way for a Jewish orphan spy to survive at a school for the Nazi elite. And that's to become a monster like them. They think she is just a little girl. But she is the weapon they never saw coming...with a mission to destroy them all.
Binding: Paperback / softback