Based on true historical records, the film unveils the harrowing atrocities committed by Japan`s Unit 731 in Harbin, China during World War II. The film exposes the horrific biological warfare experiments and inhumane human trials carried out in secrecy. It became the world`s largest base for human biological and chemical warfare experiments. Unit 731 carried out brutal live human experiments, turning countless people into tragic victims. These included spreading plague and cholera, frostbite tests, poison gas exposure, and even vivisections without anaesthesia.