A Jewish French family's tragic history during WWII is brought back to life in this adaptation of Philippe Grimbert's factual novel. When Francois (Mathieu Amalric) learns that his ageing father has disappeared, his thoughts return to his wartime childhood. The son of a gymnast father, Maxime (Patrick Bruel), and a swimming champion mother, Tania (Cecile de France), Francois' frequent bouts of ill health cause him to feel he is a disappointment to his parents. A solitary child, he lives in his own world, inventing a brother, and imagining his parents' past lives. But on his 15th birthday he learns of a dark family secret, dating from the Nazi occupation, that changes his view of his family forever, and opens up a world that he never knew existed.