London, 1938. Hanna and Jack Foster were sent to an orphanage when their parents were killed in a train crash. Hanna protects her brother, refusing to let them be separated. But when a couple choose to adopt Jack, Hanna reluctantly decides it's time to let him go. It soon becomes clear that she's made a dreadful mistake. Jack is worked like a slave and, in desperation, runs away to join the merchant navy. Hanna leaves the orphanage and takes a job looking after two children. She enjoys her work and finds new love. But war is looming and threatens to take away everything she holds dear.