Some of the cruelest deeds of Japan's war in Asia did not occur on the battlefield, but in quiet, antiseptic medical wards in obscure parts of China. Far from front lines and prying eyes, Japanese doctors and their assistants subjected human guinea pigs to gruesome medical experiments in the name of science and Japan's wartime chemical and biological warfare research. Author Hal Gold draws upon a wealth of sources to construct a portrait of the Imperial Japanese Army's most notorious medical unit, giving an overview of its history and detailing its most shocking activities. The book presents the words of former unit members themselves, taken from remarks they made at a traveling Unit 731 exhibition held in Japan in 1994-95. They recount vivid first-hand memories of what it was like to take part in horrific experiments on men, women and children, their motivations and reasons why they chose to speak about their actions all these years later.