People disappeared one after another in the city, but the police could not find any traces. Retired police detective Chen Mo came into contact with the "Gray Line" of the underlying dark network due to a commission, and discovered that all missing persons had left a very subtle symbol before disappearing. Criminal psychologist Su Tang led a new team to intervene in the investigation. The two were forced to join forces, but encountered resistance from within. As the clues were peeled away, they discovered that behind it was a huge mystery with the city as a chessboard, and the death of Chen Mo's partner was also related to this. The price of the truth is heavier than imagined.
