Helleh, originally from Berlin and of Jewish descent, is now an elderly lady, having survived years of living in concentration camps. The one thing that saved her was her ability to play the violin and become part of the Mädchenorchestra, the Girls' Orchestra at Auschwitz-Birkenau. Now with early-onset Alzheimer's disease, she lives in an Edinburgh nursing home, but her mind has become a place of torture and the shadows that lurk deep within shift and turn to take her back to the place she fears most: Auschwitz-Birkenau. Rosie, a young nursing assistant, befriends Helleh, and through their friendship is able to help unravel the hidden secrets of her tortured mind, but doing so, she exposes disturbing links to her own family's story and finds dark shadows that have lurked undiscovered for many years. Penny is Rosie's Nana; as a child evacuee, she is sent from London to the Scottish countryside, but her family are killed during an air raid on London, leaving her an orphan at the age of 12, broken and lonely. At 15 she meets a German PoW working as a farmhand, who sweeps her off her feet; she alienates everybody to be with him, then realises too late that he is not what he seemed. There is a darkness inside him that she couldn't see and now she is alone, with nobody to turn to. The far-reaching shadows that have permeated through the generations of these two families stem from the atrocities of the Third Reich and the rise of Hitler's power; shadows that have shaped the personalities of individuals, which ultimately affected both Helleh as a camp survivor and her entire family, and shadows that have affected Penny and the lives of her child and granddaughter. As the story unfolds, connections between the two families are uncovered and thus the far-reaching shadows penetrate deeper and deeper into their lives until Helleh, Rosie and Penny are left struggling to re-emerge from their own dark shadows.