Behind the glamorous financial center of Linhai City, there flows an invisible "dark river" - an underground criminal network that has been entrenched for many years. When the body of a financial elite fell from the Tianxi Building, Chen Mo, the deputy captain of the criminal investigation detachment, saw not only a simple suicide case, but a carefully woven web of conspiracy.
There was a mysterious number "714925" stored in the mobile phone of the deceased Zhou Zhengyang, which was exactly the same as the clues in an unsolved case five years ago - that was the turning point of Chen Mo's career and the same day that his father died unexpectedly. As the investigation deepened, Chen Mo discovered that Zhou Zhengyang was investigating a huge amount of money flowing through multiple shell companies before his death, and the whereabouts of this money pointed directly to the "Underground River" organization.
The unexpected intervention of criminal psychology expert Shen Ke made the case even more confusing. This mysterious woman seems to know many undisclosed details of the case, and every move she makes is like a carefully designed chess game. When Chen Mo and Shen Ke form a temporary partner, they gradually reveal the surprising connections behind a series of seemingly unrelated cases.
Internal police information continues to leak, and Chen Mo begins to doubt everyone around him. Technician Xiao Wu's unusual behavior, team leader Lin Feng's ambiguity, and even the mysterious whereabouts of his long-time partner Lao Bai... When Chen Mo received a warning from a mysterious man who called himself "The Ferryman," he realized that he was falling into a deadly psychological game.
As key witnesses are killed one after another, Chen Mo must uncover the secret that has been lying dormant for many years before the "Dark River" organization erases all evidence - about the huge amount of stolen money, the mole in the police, and the truth about his father's death.
