The story takes place in China in 1941, during the reign of the Wang Puppet Government. After unremitting efforts and disguise, the military agent Gu Xiaomeng (played by Xu Lu) finally succeeded in breaking into the Wang Puppet Government. The death of a senior official of the Japanese Intelligence Department angered the Japanese side, who believed that all this was planned and implemented by an underground party leader codenamed "Old Ghost". In order to thoroughly investigate the matter and find out the old ghost, Gu Xiaomeng and the leader of the translation team Li Ningyu (played by Janice Man), the leader of the bandit suppression team Wu Zhiguo (played by Tony Yang), the commander's aide Bai Xiaonian (played by Niu Zifan), and the director of the military aircraft department of the bandit suppression team Jin Shenghuo (played by Zhang Zhijian) were imprisoned in Qiuzhuang. The interrogators were Wang Tianxiang (played by Yu Ailei), the director of the secret service department, and Longchuan Feiyuan (played by Zhou Yiwei), the head of the Japanese secret service agency. If the old ghost cannot be found within the deadline, then none of the five of them will survive.