In 1945, as the Anti Japanese War was nearing its end, the Japanese army secretly transported a large number of poison gas bombs to China. Military Statistics ace agent Ou Xiao'an was injured while risking his life to escape from the Poison Gas Research Institute '810' and was accidentally killed by the same special agentQin Moqing, a worker, was saved but woke up to find that he had lost nearly four years of memory. In the process of exposing the Japanese conspiracy, Ou Xiao'an and Qin Moqing frequently teamed up, ultimately tearing off the mask of Japanese spies and simultaneouslyConfirmed his identity as an underground party member. However, a greater crisis is also waiting for them, where are the research data of '810' and the location of the hidden gas bomb? Faced with numerous obstacles, a group bravely advanced forwardHow should the lone warrior fight.