Zhang Weiyuan, Chongqing's ace agent in the Military Statistics Bureau, is renowned for his cunning and ruthlessness. In truth, he is "Snowy Owl," a Communist agent embedded in the bureau. To ensure that "Snowy Owl" remains a dagger lodged in the enemy's heart, ready to deal the Kuomintang a fatal blow at the crucial moment, Zhang Weiyuan has to become the bureau's Seventh Brother, a man his own comrades believe deserves to die. When his handler sacrifices himself, Zhang loses contact with the organization. After liberation, he assumes the identity of Wang Xiaowu, a former Kuomintang employee retained in service, and continues providing vital intelligence to the organization in his own unique way. Even after the organization confirms that he is "Snowy Owl," he continues working undercover to help the Public Security Bureau break up numerous spy networks. Over more than thirty years as an intelligence agent, he is hunted by the enemy and forced to endure the break-up of his family. To him, being an intelligence agent means making sacrifices, and being deemed worthy of sacrificing oneself for one's country is the finest proof of one's own value.
