How was it possible for prisoners to take photographs in the Nazi concentration camps where they were imprisoned? Some actually managed to take pictures of life (and death) in the horrible camps. Pictures that testify to both the actual conditions from an unprecedented viewpoint and to the humanity that the photographers insisted on. Today, the director Christophe Cognet returns to Ravensbrück, Dachau and Auschwitz-Birkenau in the company of a historian to install glass prints of the nearly 50 invaluable images in the locations where they were taken. Suddenly, two historical periods meet in the same field of view in a sober film about the incomprehensible.