Shanghai, 1940. Beneath the surface, undercurrents swirl. Zhou Huaijiang, a Huangpu Academy graduate and chief of the General Affairs Section, uses his smooth, adaptable manner to conceal his true purpose as he infiltrates the newly established No. 76 Special Agent Headquarters. In truth, he is a military intelligence agent codenamed “Black Swan.” A year ago, he took a bullet meant for Lin Moqun, the deputy director, to save his own life, and that was how he earned his current position.
An unexpected raid brings him face to face with Yang Qiuyan, his childhood sweetheart, from whom he was separated ten years ago. Danger is closing in: Du Hanqiu, a Communist Party liaison, has been arrested; the traitor “Sparrow” is plotting in secret; and Yang Qiuyan is in peril. Zhou Huaijiang must follow military intelligence's orders and counter Lin Moqun's schemes, all while choosing between a decade of shared history and a difference in beliefs. He must secretly help Yang Qiuyan rescue Du and root out the traitor, while guarding his identity as an agent. In this treacherous maze of a chaotic age, he must tread carefully, for one wrong move could spell utter ruin.