Zheng Yaoxian, the ace agent of the Chongqing Military Control Commission, is famous for his cunning, wit and ruthlessness. Zheng Yaoxian is actually a Communist Party agent "Kite" lurking in the Military Control Commission. In order to ensure that "Kite" always stabs the enemy's heart like a sharp knife and gives the Kuomintang a fatal blow at the most critical moment, Zheng Yaoxian has to become the sixth brother of the Military Control Commission in the eyes of his comrades. The sacrifice of his superiors made him lose contact with the organization. After liberation, he changed his name to Zhou Zhiqian, a member of the Kuomintang, and continued to provide important intelligence to the organization in a unique way. After his identity as a "kite" was confirmed by the organization, he still assisted the Public Security Bureau in uncovering many hidden spies in a covert way. In his more than 30 years of career as an intelligence officer, he was hunted down by the enemy for a long time and endured the separation of his wife and children. For him, intelligence officers themselves mean sacrifice, and the fact that a person is qualified to sacrifice for the country is the best proof of his own value.