Police officer Lin Kai is assigned to be an undercover in a drug cartel by his supervisor Li Jianguo. As he gradually penetrates into the “Twin Eagles” drug cartel, he discovers that the big boss, Eagle, is connected to a crime case investigated by Li ten years ago. Li was then an undercover. In order to gain Eagle’s trust, Lin is forced to become a drug addict. Fighting against the drug addiction was hard enough, he must not lose his focus on locating Eagle’s drug production base. In the process, Lin finds out that Eagle had seized Li’s work partner, Ning Zhi, for ten years just waiting for the day he could take the revenge. Li had to save Ning even it might cost his life. It is not only about fighting the drug dealers now, it is an extraordinary mission!