France, 1916. Sophie Lefevre must keep her family safe whilst her adored husband Edouard fights at the front. When she is ordered to serve the German officers who descend on her hotel each evening, her home becomes riven by fierce tensions. And from the moment the new Kommandant sets eyes on Sophie's portrait - painted by Edouard - a dangerous obsession is born, which will lead Sophie to make a dark and terrible decision. Almost a century later, and Sophie's portrait hangs in the home of Liv Halston, a wedding gift from her young husband before he died. A chance encounter reveals the painting's true worth, and its troubled history. A history that is about to resurface and turn Liv's life upside down all over again . . . In 'The Girl You Left Behind' two young women, separated by a century, are united in their determination to fight for what they love most - whatever the cost.