The plot tells the story of the murderer of a mysterious case in Nandu City in 1997 who reappeared 13 years later. The real murderer was never traced back then. The criminal guard Zhengrong was hit hard and left the front line, while the once fledgling new police officer Lu Xingzhi has lost his innocence and become a rigorous police officer.A meticulous criminal investigation expert.Thirteen years later, many coincidences in the case evidence brought the criminal police master and apprentice together again. When faced with doubts, the two peeled off the cocoons and worked together to hunt down the real culprit.

The origin of the story is that in 1997, a major case occurred in Nandu City.The criminals had certain counterintelligence capabilities, but the detection technology of that era was limited, resulting in the real murderer not being caught.This mysterious case lasted for 13 years.A similar major criminal case surfaced again in 2010. Based on the traces left by the murderer at the scene, it can be concluded that the 1997 case was committed by the same murderer.Wei Zhengrong and Lu Xingzhi's master and apprentice once again joined forces to pursue him.

Due to the death of his first love Bai Xiaofu and the failure to solve 97% of the cases, Wei Zhengrong withdrew from the front line of criminal investigation.Wei Zhengrong (played by Chen Jianbin) served in the army before becoming a criminal police officer.During this period, he thought he was going to be seriously ill and die, so he asked someone to bring a message to his fiancée Bai Xiaofu, asking her to remarry.Bai Xiaofu hated Wei Zhengrong's selfishness and how he would marry anyone at will.Later, Wei Zhengrong did not die, but Bai Xiaofu got married, so he married Hu Haixia (played by Liu Mintao).

Bai Xiaofu's marriage of convenience was very unhappy, and she died shortly after the divorce.Wei Zhengrong's marriage also broke up due to overwork.After the divorce, his ex-wife became seriously ill and he raised his son alone.In general, the work of a criminal police officer is very hard, and the family members of the criminal police officers must put in more energy.In addition, the reason why Wei Zhengrong and Hu Haixia broke up was not because their relationship was completely broken down, but because Hu Haixia could not accept Wei Zhengrong solving the case day and night.13 years ago, Wei Zhengrong left the front line of criminal investigation because he could not solve the case and could not overcome the obstacles in his mind.However, he trained Lu Xingzhi (Chen Xiao), an excellent criminal investigation expert, from rookie to independent.

Lu Xingzhi worked harder for his career than his teacher.When he first joined the criminal police team, he felt like vomiting when he saw corpses, so he worked hard to adapt.Due to his lack of practical experience, he not only enthusiastically absorbed the lessons Wei Zhengrong taught him, but also humbly learned from everyone around him.Although Wei Zhengrong withdrew from the front line, the situation in 1997 was still a concern for him.After his apprentice Lu Xingzhi became a school captain, he did not give up his vigilance about this case.Lu Xingzhi even adopted the victim's daughter and named her Lu Anning, which means a peaceful life.

In the end, Lu Anning found out Lu Xingzhi's identity as a criminal police officer. When he saw him, he thought of his dead relatives and was afraid that Lu Xingzhi would be killed before he got off work.For Lu Anning's healthy growth, Lu Xingzhi had no choice but to divorce his wife Yang Man, just so that Lu Anning would never see Lu Xingzhi again in her life, and so that Lu Anning would no longer have nightmares and insomnia every night.If Wei Zhengrong broke up with his first love Bai Xiaofu, it was because he was afraid of delaying Bai Xiaofu's youth.Now, Lu Xingzhi and Yang Man are separated to raise the victim's children.Great!