Clare Hartill is a brilliant, commanding teacher at a private all-girls boarding school: the undisputed queen of her own small kingdom. But her tightly controlled world is disrupted when she meets Alywnne Durand, a nineteen-year-old with no formal training. Alywnne's innocence and openness endear her to the secretive Clare. Alwynne is drawn to Clare's intelligence and sophistication. The two women fall headlong into an all-consuming friendship, and begin planning a life together. But their relationship is tested when an exceptionally gifted student named Louise enters their orbit. Louise will do anything to win Clare's approval. Meanwhile, Clare's jealous and manipulative nature slowly pulls Alwynne away from her friends, her students, and her family-anyone, in fact, who is not Clare Hartill.