On October 1, 1949, the War of Liberation entered the end of the third stage. The Kuomintang was entrenched in the southeastern town of Guangzhou and resisted stubbornly. However, in the hopeless situation, the Kuomintang planned to destroy the infrastructure of Guangzhou before withdrawing to Taiwan to obstruct liberation. Yan Haiqing (played by Guo Xiaodong), a CCP intelligence officer lurking inside the Kuomintang, has followed the director of the Military Control Commission Xia Huimin (played by Sun Chun) for many years. This time he accepted the organization's task and stole the details of the obstruction plan from Xia Huimin. In Guangzhou, shrouded in a solemn atmosphere, Yan Haiqing carefully moved forward in the dangerous work of dish intelligence. He was accompanied by only a young and simple maid Qiu Xi (played by Jiang Yiyan). Facing the latter's grateful love, Yan Haiqing evaded and could not face it. At the same time, Xia Huimin's view of this suspicious subordinate seemed to go beyond the general working relationship, and there was something else hidden...