The cyanide solution in the penicillin bottle uncovered a series of murders, and Cheng Moqing discovered that Japan's 731 unit was causing cholera vaccine failure. In the autopsy room, he used a scalpel to cut open the stomach pouch of the Japanese colonel's corpse, took out the microfilm soaked in formalin, and finally mixed the fake epidemic report into the file box of the League of Nations investigation team. The thermometer in the refrigerated cabinet in the morgue was actually the detonator that detonated the opium warehouse on the dock.
