Ma Haotian (played by Andy Lau), Zhang Ziwei (played by Nick Cheung) and Su Jianqiu (played by Louis Koo), good brothers who grew up together, work together in the anti-drug division of the police force. After an operation that temporarily changed the plan, Jianqiu wanted to quit because he could not live a normal life with his wife (played by Yuan Quan) as an undercover agent, but under the persuasion of A Tian and Ziwei, the three decided to make a final fight. Jianqiu followed the drug dealer boss Heichai (played by Lam Kwok Bun) to Thailand to connect with drug dealer Bobby (played by Lu Huiguang), in order to meet the biggest target of the operation, "Eight-Faced Buddha" (played by Lu Haipeng). A Tian followed up with Ziwei and his colleague Ayi (played by Wu Tingye). Due to the poor cooperation of the Thai police, Jianqiu's identity was exposed. Although Jianqiu promised A Tian to continue to complete the transaction, the fuse of failure had been buried. On the day of the transaction, the police were almost wiped out. In the critical moment, A Tian held the Eight-Faced Buddha's daughter Mena (played by Bo'er) hostage and prepared to escape. The Eight-Faced Buddha promised that as long as Mena was returned, A Tian could take away one of Jianqiu and Ziwei. The one who was not chosen would be pushed into the crocodile pool. Faced with the choice, A Tian was in a dilemma...