Unit 731

The Epidemic Prevention and Water Purification Department of the Kwantung Army, more commonly known as Unit 731, was a covert biological and chemical warfare research unit of the Imperial Japanese Army that practiced lethal experimentation humans, including infection of prisoners of war with diseases, exposcure of POWs to chemical weapons, and vivisection. Unit 731 was established by General Shiro Ishii in 1936 in the Pingfan district of Harbin, China, after a previous facility was shut down in 1935 in the wake of a prisoner escape. It operated throughout both the Second Sino-Japanese War and World War II. In 1945, after Japan surrendered, General Douglas MacArthur brokered a deal that saw the scientists of Unit 731 avoid prosecution by turning over all research to the United States.

Unit 731 in The War That Came Early
In 1940, Unit 731 saw an influx of Soviet prisoners of war captured by Japanese forces at Vladivostok. There the POWs, dubbed "logs", were subjec to a variety of experiments under the supervision of Colonel Shiro Ishii. This continued on, despite the fact that a peace had been concluded between Japan and the USSR not long after Vladivostok fell.