Introduction
Three years ago, criminal police officer Cheng Yan resigned because he misjudged the "numbered case" and led to the imprisonment of innocent people. Three years later, a serial murder case imitating the "Numbering Case" appeared in the city, and a string of numerical codes was left at the scene. Cheng Yan was recalled by Su Qing as a 'special consultant' to reorganize the 'case tracing team'. They found that each string of codes corresponded to a criminal psychological profile, and the 'architect' was the manipulator behind the scenes. Cheng Yan and Su Qing gradually uncovered the truth behind the code during the investigation, but every step they took touched the abyss of the old case, and the team members each had their own secrets, making the road to solving the case even more confusing.
