Spanish photographer Francesc Boix, imprisoned in the Mauthausen-Gusen concentration camp, works in the SS Photographic Service. Between 1943 and 1945, he hides, with the help of other prisoners, thousands of negatives, with the purpose of showing the freed world the atrocities committed by the Nazis, exhaustively documented. He will be a key witness during the Nuremberg Trials.

When flaky novelist Mario turns up one day at the school where Daniel teaches, the educator is convinced the writer is a spirit from his repressed past, buried deep in his subconscious. As children, the two might almost have been brothers. But the marriage between Daniel’s father and Mario’s mother never materialised. This unexpected re-encounter brings both families together. When Mario slits his wrists and dies, Daniel and his wife Laura provide a home for the dead man’s daughter. Laura, who is childless, loves the girl from the moment they meet, but Daniel feels increasingly nervous around her. The demons of his past guilt continue to torment him. Daniel suffers agonies – until things come to a head during a show down in the mountains.