First of all, let me state that this story is purely fictional. The background of the work is the newly liberated Jiangnan city of eastern Guangdong. Suspecting that the Kuomintang authorities were conducting poison gas research here, the new government organized a group of scientists to conduct on-site exploration in order to find out the secrets of the air-raid shelters in Boya Mountain behind Yuedong City. After the war, the Secrecy Bureau personnel who stayed in eastern Guangdong implemented their plans step by step by assassinating scientists. Li Qiwei, a returned student who was ordered from the Beijing Criminal Investigation Division to rush to eastern Guangdong to solve the case, cooperated with Wang Shi'an, the operations captain of the Public Security Bureau. Faced with the cunning and clever Kuomintang agents, can they uncover and stop the agents' conspiracy?