Which of Chen's films is about the underworld?

Chen's film about underworld is Infernal Affairs 3 is endless. The film tells the story that Liu Jianming Andy Lau was investigated by the police 10 months after he was killed in Tony Leung Chiu Wai, Chen Yongren, and his mental state became worse and worse, but he firmly believed that the situation would turn around soon. The young superintendent, Yang Jinrong Liming, is an eccentric in the eyes of his colleagues. He is moving towards the top of the police force with extraordinary achievements. In order to find out Yang Jinrong's true identity, Liu Jianming began to investigate him.

Gradually discovered old business partners are inextricably linked with. In order to kill Yang Jinrong and keep his identity from being exposed, Liu Jianming, who has been eager to be a good person for a long time, began to search for evidence after evidence, but always fell short when he was closest to the truth.

Shen Cheng, played by Chen in the film, is from mainland China. He is a private entrepreneur from Taiyuan, Shanxi Province, with a complicated background and an unknown amount of funds. After Hong Kong's return to China, it became a new immigrant in Hong Kong, and was implicated in the underworld boss Chen Han at that time. The two men cooperated to establish the largest smuggling network in the Pearl River Delta, which seems seamless, but in essence they have their own plans.