Jacques Altmann is a survivor. A German-born Parisian Jew, he was an early resistor, before being betrayed and captured in 1943. Transferred to the camp at Drancy, he then worked as forced labour for the Nazis until being shipped to Auschwitz. He took part in a death march to Buchenwald and weighed just 29kg when he was finally liberated. His is an utterly extraordinary story.