On October 10, 1942, the Wang Puppet Regime held a grand celebration of the National Government. However, a series of assassinations of military and political officials made Wang Tianxiang (played by Wang Zhiwen), the director of the secret service, feel very uncomfortable. During the torture and interrogation of the female assassin (played by Liu Weiwei), he obtained a key piece of information-the underground party code-named Lao Gui had infiltrated the bandit suppression headquarters. Wang Tianxiang, who was eager to make a contribution, immediately reported to Takeda (played by Huang Xiaoming), the head of the Japanese Imperial Army's secret service agency. The two then set a trap in Qiuzhuang, intending to force Lao Gui to show up by releasing false news. Among the suspects were the commander's aide Bai Xiaonian (played by Su Youpeng), the director of the military aircraft department Jin Shenghuo (played by Yingda), the bandit suppression captain Wu Zhiguo (played by Zhang Hanyu), the leader of the translation team Li Ningyu (played by Li Bingbing), and the administrative receiving and sending specialist Gu Xiaomeng (played by Zhou Xun). In the process of suspicion and investigation, Takeda and Wang Tianxiang used both soft and hard means, but the development of things was unexpected...