The Escape Artist by Jonathan Freedland. The story of Rudolf Vrba who at the age of 19 in 1944, escaped from Auschwitz with a fellow inmate, determined to tell the world what was happening inside the camp. Vrba had survived for 2 years in Nazi captivity, narrowly avoidng death multiple times. All the while committing to memory virtually all of the shipments of (largely) Jewish prisoners brought into the camp as either slave labor or more likely, to be summarily murdered. With his incredible talent for numbers and details, he memorized which countries the trains arrived from, when they arrived and how many prisoners were aboard them. And of course, he paid careful attention to the number of prisoners sent to the gas chambers. Vrba eventually tallied approximately 1.7 million deaths before finally escaping the camp to alert both the Jewish communites still remaining in Slovakia and Hungary and the allied leaders. Unfortunately, his horror story went largely ignored by those who could have perhaps saved hundreds of thousands of lives during the waning days of the war, had they only heeded Vrba's warnings. Including some Jewish leaders, incredibly.