About the events of the final stage of the Second World War - the defeat of the Soviet and Mongolian troops of the best Kwantung Army. In the laboratory of the Japanese General Ishii Shiro, bacteriological weapons were created. The experiments were conducted on prisoners of war and political prisoners. Epidemiologist Dmitry Sokolov was instructed to solve the mystery of this laboratory. By the price of his own life he fulfilled the task. The march of Soviet and Mongolian formations through the sands of the Gobi and the spurs of Hingan was not only a brilliant military operation, but also a warning of the use of bacteriological weapons by Japan ...