The undercover in this film is not Li Zhongjiu, but Li Zicheng. Li Zicheng is undercover sent by the police, represented by Cui Minzhi. Li Zhongjiu is an important figure in the group. He is competing with another man for the next president. They fought privately, and Li Zicheng was an undercover 10 policeman. The role played by Huang Zhengmin and the role played by Li Zicheng should be better brothers, because the note given to him in the other party's mobile phone is a brother, which shows that he has gained the trust of the other party.

When the superior told Li Zicheng that he had received a new task and hoped that Li Zicheng could continue to play the role of undercover to ensure that the police could control Kinmen, Li Zicheng didn't want to continue to be undercover. Because he has been in this dark world for a long time, he has great inner pressure and has not lived a normal life for a long time. My role is still poor. Later, he learned that Ding Qing, played by Huang Zhengmin, already knew his identity. He felt surprised and a little guilty at the same time, because the other party really regarded him as a brother.

Although Ding Qing already knew his identity, he didn't hit each other. Although two people belong to two worlds, the brotherhood between them is real.

Ding Qing was later seriously injured. On his deathbed, he told Li Zicheng that he hoped Li Zicheng would make up his mind to take control of his own destiny. This is the warning his brother got before he died. After that, everyone who knew Li Zicheng's identity died, and Li Zicheng happened to be the backup. He became the next boss of the dark world.