This book tells the story of a five-person folk reasoning team that solves a series of complicated and major cases in the city. They each have their own expertise. The cases involve not only criminal investigation, psychology, network, medicine and other multi-dimensional fields, but also closely involve the law, morality, power, money and human relationships in real society. Each volume uses a separate and progressive case to advance the main line. At the same time, the protagonists' individual and overall growth lines and the complex and subtle multi-line relationships between the teams gradually reveal the truth of a serial unsolved case that has been dusty for many years. Under the collision of fascinating reasoning, meticulous logic and distinctive characters, the story shows a realistic, tight-paced and echoing analysis of human nature and the pursuit of justice.