Summer of 1945. The Soviet command moved to the far east some of the troops released in the west to attack the Japanese army in manchuria. Alexei khlamov, a Russian emigrant infected with smallpox, is entering one of the divisions. He says that the Japanese military detained him in the so-called "unit 731". In order to ascertain the credibility of the fugitive's testimony in the rear of the Japanese sent a reconnaissance team kravtsov, homeland and resident Chen in Japan. Colonel takeshi tanaguchi, head of laboratory security, is trying his best to prevent the Soviet troops from detecting secret designs. Novices of a nearby buddhist monastery come to help the reconnaissance group.