Lidia Maksymowicz was just 3-years-old when she arrived in Auschwitz-Birkenau with her family. Lidia was picked by Dr Josef Mengele for his experiments and sent to the children's block, where she survived 13 months of hell. Injected with infectious diseases and desperately malnourished, she came close to death. Her mother -- who risked her life to secretly visit Lidia -- was her only tie to humanity. By the time Birkenau was liberated her family had disappeared, her mother presumed dead. Lidia was adopted by a woman from a nearby town. Too traumatised to feel emotion, she was not an easy child to care for, but she came to love her adoptive mother and her new home. Years later, she discovered that her birth parents were still alive in the USSR and wanted her back. Lidia was faced with an agonising choice...