Criminal police captain Meng Dong received a floating corpse case as soon as he took office. Shi Shuisheng, a fisherman in the small town of Zhubei, where the incident occurred, turned himself in voluntarily, which made Meng Dong suspicious. From Shi Shuisheng's perfect confession, Meng Dong found a clue and pointed the finger at the local bully Li Laosan. After some investigation, Meng Dong arrested Li Laosan who accidentally killed someone. Just when the police team was about to celebrate, the autopsy report dispelled Meng Dong's joy, and a new clue dragged the case into a new vortex.