In Shanghai in 1940, undercurrents were surging. Zhou Huaijiang, the chief of the General Affairs Section who graduated from Huangpu, uses his all-around appearance to conceal himself from the public and lurk in the newly established No. 76 Agent Headquarters. His true identity is the military special agent "Xuan Hu" - a year ago, he took a fatal shot for self-protection deputy director Lin Moqun, and only got his current position.
A sudden arrest made him unexpectedly reunited with his childhood sweetheart Yang Qiuyan who had been separated for ten years. At this time, crises are brewing: Red Party liaison officer Du Hanqiu is arrested, the traitor "Sparrow" hides murderous intentions, and Yang Qiuyan is in danger. Zhou Huaijiang has to abide by the military commander's orders and deal with Lin Moqun's calculations, but also has to choose between ten years of friendship and differences in beliefs. He must secretly help Yang Qiuyan save people and eliminate the rebellion. At the same time, he must stick to his identity as an agent and work step by step in the chaos of troubled times. The slightest mistake will be irreversible.
