Sixteen years ago, Detective Xia Hui led Zhao Haiyang and Fang Cheng in the pursuit of a murderer responsible for a family massacre. Due to Zhao Haiyang's youthful impulsiveness, Xia Hui tragically lost his life. Sixteen years later, burdened with regret and a deep hatred for criminals, Zhao Haiyang has become the Deputy Director of the Dongzhou City Public Security Bureau, while Fang Cheng has become a technical expert. Dongzhou City faces new challenges from emerging crimes. Utilizing advanced technologies, Zhao Haiyang and Fang Cheng effectively combat crime. Police reforms and technological applications have left criminals with nowhere to hide. However, Zhao Haiyang's wife, An Ping, encounters an accident during a case and is demoted to a local police station. As Zhao Haiyang and Fang Cheng are determined to track down the real murderer behind the massacre case from sixteen years ago, they uncover a powerful force working behind the scenes, with all clues pointing towards Zhao Haiyang's former superior, Liu Guangsheng. The two join forces to reveal the truth and vow to bring the true culprit to justice.