In 1988, criminal Wei Guoping (played by Zhang Yi) witnessed the sacrifice of his comrades in the pursuit of a serial mystery case, but the murderer escaped. This incident became a knot in Wei Guoping's heart. Eight years later, a horrific murder occurred in Ningjiang City. At this time, Wei Guoping had grown into a mature criminal police captain. In the process of leading the team to investigate, he successively solved many related cases, but the murder case was always full of doubts, and many clues were related to the serial mystery case eight years ago. These discoveries made Wei Guoping excited, but also became an obstacle for him to judge the case later. In the process of advancing the case, a huge criminal group gradually surfaced...