Austria, 1940s: Yugoslavian Nico Antonov is just one of more than 200,000 people imprisoned in the Mauthausen concentration camp. When fate brings him into contact with Lena Lang, he finds an ally. SS officers have charged Spanish POW and photographer Mateo Baca with recording the events and prisoners of Mauthausen and to make five copies of the collected photo book for the Third Reich’s leaders. But Mateo also creates a sixth book to be smuggled out of the camp—where Nico entrusts Lena to hide it and protect their secret. Australia, 1980s to present day: When teenager Hannah Campbell discovers her grandfather Nico’s mysterious photo album, filled with horrific visions of suffering and cruelty, the barbarities of World War II no longer feel like ancient history. Haunted by the images for years, she pursues the truth behind her grandfather’s incarceration.