Anna's personal life is in crisis. Her marriage is struggling, and the disastrous affair she began as consolation has now become a millstone around her neck. The place where she feels most secure is the safe and ordered world of the classroom; as a teacher she happily follows the rules, works hard and gets results.

Then the beautiful Kali arrives in her English group, a girl who is bright, unsettling, vulnerable and in need of guidance from an older woman. What could be more natural than for a caring teacher to show concern for a troubled pupil? Anna believes the friendship can save them both.

But when that friendship begins to tip over into something more intense, Anna finds her professional and domestic lives caught up together in a spiral that threatens to destroy everyone she ever cared about.