Baoyu (Lin Shen) is an undercover policeman lurking in a drug trafficking gang. After years of investigation and evidence collection, he finally took down a drug den. Baoyu thought he could say goodbye to his life of fear and fear and return to the police force, but he received another mission. Another drug trafficking gang is growing rapidly and is inextricably linked to the gang he was undercover in before. Tangguo (Li Qin), the daughter of the drug dealer leader, was kidnapped by her enemies. Fortunately, Baoyu rescued her and Baoyu got the opportunity to go deep behind the enemy. However, his true identity was repeatedly threatened by being exposed. In order to protect Baoyu's safety, Director Fang Qinglong (Zhang Jiayi) sent investigator Qin Yue (Zhai Tianlin) to secretly support him. On the road of love and law, loyalty and morality, Baoyu went further and further.