In Shanghai in 1943, Chen Qian, a military agent, was ordered to assassinate the Japanese, but fell into the trap of Yujiro Iida, the head of the Japanese Mei Agency. Chen Qian was in danger, but fortunately, he was rescued by "Feitian", a Communist Party member lurking in the Mei Agency, and escaped. He accidentally learned about the Japanese conspiracy. In order to stop the invaders' sinister plan, Chen Qian began to receive special training and disguised himself as a Japanese envoy to visit the Mei Agency again. Chen Qian, who went deep into the enemy camp, was cautious in the dark and treading on thin ice. With the help of Communist Party member Chunyang, he repeatedly turned danger into safety. When several Communists died, Chen Qian was deeply shocked and gradually strengthened his communist beliefs. After that, he worked together with the underground Communist Party organization to successfully smash the Japanese conspiracy. After the defeat of the Japanese army, Chen Qian returned to the military as a secret Communist Party member, and worked hand in hand with the new "Feitian" of the Communist Party to share life and death, thwarting the "Nirvana Plan" of the military and ushering in the peaceful liberation of Chongqing.