Delivery boy Lu Xingzhou has a secret: he remembers every alley and every intersection in the city. While delivering food, he witnessed corpses being dismembered and thrown away, and was forced to cooperate with the police. Policewoman Shen Jinghong doubts his motives, but she doesn't know that what he is pursuing is far more than the current case - twenty years ago, his father, a criminal police officer, was wrongfully imprisoned and died in depression after being released from prison. Nowadays, serial murders occur frequently in Jiangcheng, including demolition explosions, missing girls, and armed robberies... Lu Xingzhou rides an electric bicycle through the dark side of the city. Hidden in the food delivery box are notes left by his father and a police badge that he has never handed over. The truth lies in the darkness, and he chooses to walk against the light.
