During World War II, Japanese scientists, led by Shiro Ishii, built a medical facility in Manchuria. It is in this place, Unit 731, that Ishii and his scientists conducted some of the most horrific war crimes of the 20th century. The goal of Unit 731 was to experiment with germ warfare, with the ultimate aim of using these weapons on the United States during the war. Experiments were conducted on Chinese civilians, soldiers and American prisoners of war. They ranged from live dissections to the deliberate infection of surrounding villages with diseases such as the bubonic plague. Now, over fifty years later, activists, journalists and historians are uncovering the story of Unit 731, and the American complicity that let these war crimes go unpunished.