Davinsky Labour Camp, Siberia, 1933: Two things have sustained Sofia Morozova through the cold, hunger and hard labour: the prospect of one day walking free; and the stories told by her friend Anna, of her upbringing in Petrograd and her fervent love for Vasily. When Anna falls gravely ill, Sofia promises to escape the camp and find Vasily. But times have changed. Her perilous search takes her from industrial factories to remote villages, where she discovers a web of secrecy and lies, but also bonds of courage and loyalty - and an overwhelming love that threatens her promise to Anna.