Nora is just 12 when the war breaks out and she joins train-loads of evacuees leaving London's East End for the safety of rural Kent. Her surrogate family, the Rivers, are unlike anyone she has ever met and she soon comes to love her new life with them, in particular with their daughter Grace. The two become as close as sisters, although to Nora's confusion, even this is not quite as close as she would like. What happens is a secret that will eat away at Nora for the rest of her life.