Shanghai, 1940. On the isolated island, there are turbulent undercurrents, and every step is a chess game of life and death.
Military agent Yu Mingzhe, codenamed "Qing Feng", was injured during a reporting operation and was accidentally rescued by his former Fudan classmate Su Nianzhen. The once ideal young people now belong to different camps - Yu Mingzhe serves the military command, while Su Nianzhen is the secret liaison of the underground party. The brief encounter in Yuye Bookstore planted the seeds of trust and suspicion.
Returning to the battlefield, Yu Mingzhe shoulders a double desperate mission: to get close to Lin Mo, the telecommunications section chief of No. 76 Who holds the core secrets, to dig out Japanese and puppet intelligence; at the same time, he uncovers a deadly traitor codenamed "Grey Shadow" lurking in the top military command. Su Nianzhen was also ordered to use an old relationship to spy on the military commander's movements from Yu Mingzhe. Fate pushed these old friends into the same chess game, becoming "dangerous dance partners" who test and exploit each other but cannot be ignored.
When top-secret information about "Operation Moonlight" concerning millions of lives in Chongqing emerges, trust faces the ultimate test. Faced with the "grey shadow" within the organization, Yu Mingzhe made a shocking decision - to send the information through the hands of Su Nianzhen. Although this move turned the tide, it also ignited the raging fire of the military's internal investigation and pushed itself to the edge of the cliff.
Crisis ensues. On the 76th, the list of potential personnel of the military command was obtained, and the butcher's knife was hanging high. Yu Mingzhe struggled painfully between protecting his comrades and preserving his identity. Although his desperate early warning operation saved several people, it caused an uproar. Lin Mo was subjected to internal review due to his contact list, Su Nianzhen was arrested by No. 76 On suspicion of "collaborating with the Communist Party", and Yu Mingzhe committed suicide
