Unit 731 is a name associated with some of the most sickening war crimes committed by Japanese forces in China during World War II. It was responsible for biological and chemical warfare experiments, carried out in the guise of "disease prevention" and "water purification", which left thousands of Chinese people dead, mutilated, or infected. CGTN host Mike Walter visits an archive where every yellowed page is filled with indescribable pain and every chapter cries out in condemnation of the excesses of human cruelty. Join him in reflecting on one of the most harrowing episodes in the history of World War II.