Ten years ago, when Zhao Haiyang and Fang Cheng were chasing the murderer of a family-destroying case, Zhao Haiyang's unusual behavior alerted the criminals, leading to the sacrifice of his master Xia Hui. Ten years later, Zhao Haiyang grew from an ordinary police officer to the deputy director of the Dongzhou Public Security Bureau, and Fang Cheng returned to Dongzhou with his own technical achievements to carry out police reform. The two met and were not as friendly as they imagined. Zhao Haiyang was full of prejudice against Fang Cheng, and at the same time, he was full of resistance to the police reform ideas he brought. In recent years, various new crime models have not only overwhelmed Zhao Haiyang, but also caused his wife An Ping, who is also a police officer, to be demoted to the police station. When he was at a loss, Fang Cheng used new criminal investigation techniques to solve many problems for Zhao Haiyang. Intelligent transportation, synthetic investigation centers, and grid construction make it impossible for criminals to hide, the anti-fraud center makes it impossible for fraudsters to start, and the establishment of the Environmental Food and Drug Detachment allows the people to eat more assured. The police reform work has also been gradually carried out like a spring breeze and rain, and initial results have been achieved. Just when everything is going smoothly, the murderer of the murder case fifteen years ago surfaces. Zhao Haiyang and Fang Cheng join forces to bring the murderer to justice. However, during the investigation, there seems to be a powerful force that always hinders the investigation of the case...