During the Republic of China, Chen Yanqiu, the inspector of the patrol house in the Shanghai Concession, fished up the body of an unknown man from the Suzhou River. The deceased had strangulation marks on his neck, a gang brand burned off his back, and a roll of mysterious film hidden in his stomach. As the investigation deepens, Chen Yanqiu is gradually involved in the struggle between various forces in the concession. Behind a seemingly ordinary drowning case, there is a secret that can shake the dark order of the city.
