"Infernal Affairs 3" by Chen Daoming and Shen Cheng. It has little to do with movies, and is more about writing romance stories through characters.
The clues of Shen Cheng in Infernal Affairs are as follows: Shen Cheng is a fire dealer from Mainland China who goes to Hong Kong to trade fire with Han Chen, the leader of the triad. Han Chen didn't trust Shen Cheng and tried many times before the transaction. When the transaction was finalized, not only did Hei Chi Hei collect the goods, but they also called the police. During the confrontation, Shen Cheng met undercover Chen Yongren and policeman Yang Jinrong (Leon Lai), and the three became friends. After the transaction failed, Shen Cheng returned to Beijing. However, Chen Yongren was killed by Liu Jianming. Yang suspected that there was a mole in the Hong Kong police force, but he could not find it out, so he contacted Shen Cheng. After Shen Cheng came to Hong Kong again, he designed with Yang to find out that Liu was an undercover agent. During the final confrontation with Liu, Yang was shot in the head and killed by Liu.
For Shen Cheng's identity, please refer to this article: https://movie. Douban. Com/review/7633527/
Not an undercover agent, but closer to a white glove with an X-party background, similar to the protagonist in "Lord of War". At the same time, when the transaction is hot, help the G side deal with some matters that cannot be seen in the light.
Purpose: From a battle of wits and courage to mutual redemption