Anyone who has seen Infernal Affairs 2 knows that when Chen Yongren and Huang Qiusheng were talking in front of the tombstones of two dead policemen, they said that they kept all the evidence of Ni Xiaoyong's crime in a safe, and there were many words in it that they could not write. If they don't understand, they can go to him, but don't screw up the date because he has been waiting for a long time.

So he really can't write a lot of words, and it's normal to write that dart wrong. This shows the drama of the film, and it is precisely because he just can't write this word that Andy Lau's true identity is discovered.

Story background

199 1 year, 18-year-old underworld member Liu Jianming followed the instructions of his eldest brother Chen Han (Ceng Zhiwei) and entered the police academy to study and became a police undercover. At the same time, another police academy student, Chen Yongren (Tony Leung Chiu Wai), was apparently forced out of school by the police, but in fact he was asked to work undercover in the underworld.

After graduating from the police academy, Liu Jianming successfully entered the police station, and his position was promoted step by step. He has become a member of Group A of the Criminal Intelligence Service. During this period, he used various opportunities to provide Chen Han with a lot of information.

Over the years, Chen Yongren gained the initial trust of Chen Han, but because Chen Han's case has never been solved, he can only stay in the gang forever, and only Inspector Huang (Huang Qiusheng) has one-way contact with him.