In 1942, deep in the Taihang Mountains, Zhang Tao, commander of the Eighth Route Army's reconnaissance company, was ambushed by the Japanese "Skeleton Regiment" during a mission to escort medicine. This encounter, which should have been without any suspense, was overshadowed by the Eighth Route Army's standard weapons in the hands of the regiment soldiers. When Zhang Tao found a pocket watch engraved with his sister's date of birth from the seriously injured Japanese military doctor Michiko Sato, a shocking conspiracy emerged - the Japanese army was secretly building twelve "bacterial cocoons" in the North China Plain, and Zhang Tao's closest relatives were actually the operators of this biological and chemical war.
