For several months, the Nanshi Municipal Bureau's task force received anonymous mailed letters from time to time. Guo Mang, the young captain of the city bureau's task force, felt strange and led the members of the task force to investigate secretly. With the help of deputy captain Rong Xu and Peng Shengyi, a college classmate who is now teaching at Nanshi Public Security University, they went deeper and discovered a shocking conspiracy. During the investigation, Peng Shengyi introduced him to the mysterious genius Ye Zihou, a criminal investigation expert and lawyer. The Nanshi task force specially hired Ye Zihou as a consultant to help solve many cases. However, each of these cases actually pointed to those anonymous emails... What kind of unspeakable secrets are hidden in them? What kind of entanglements will happen between the leader of the task force, Guo Mang, and the mysterious genius Ye Zi?