Binhai City is a modern city where prosperity and darkness coexist. Gu Chen, the deputy captain of the criminal investigation detachment, a crime-solving genius who has become calm and almost cold due to past trauma, and Lin Qingyan, a criminal psychology expert newly transferred from the city bureau, a gentle woman who firmly believes that human nature is good and is good at discerning people's hearts, are bound together by fate. What they faced was a serial revenge plan planned by the "Dark River" organization that spanned more than ten years and targeted "evil" that cannot be punished by law. Each case is like a puzzle piece that will eventually point to a dusty huge conspiracy that is enough to shake the foundation of the entire city. In the process of tracing the truth, Gu Chen and Lin Qingyan not only had to fight wits and courage with highly intelligent criminals, but also faced the "shadow of the dark river" in their hearts, and in crisis after crisis, they went from initial mutual rejection to final dependence on life and death.
