I have seen books and movies. Generally speaking, the two policemen in the early stage were both boxers (both famous, as if they had a high winning rate). Under the hype of the police station, they played a game, the purpose of which was to attract people's attention, let the bill in favor of the police pass, and let two experts get to know each other, that is, Li and Butch. They get along well and become close friends, including Li's girlfriend Kay. In fact, Kai has always been in between. Suddenly, a big case came, you should know, and at the same time, a person who Li was particularly concerned about also came out of prison-Kay's ex-boyfriend. The film didn't show that he was planted by Li, robbed in the bank and saved Kay. Her ex-boyfriend has been abusing Kay, and Li has also got a lot of money. That's why Li, as a policeman, is rich. Back to the main line, Li and Butch devoted themselves to investigating Dahlia, but Li mysteriously disappeared. At the same time, Butch meets a woman who is very similar to the victim-Madeleine, and seems to be related to this case. From then on, Butch began to observe Madeleine. Finally, in order to handle the case, he approached her and determined the "relationship", but never found the murderer. Suddenly one day, he found Li's body (in Mexico, written in the book), and Butch went to Mexico. From contact with Madeleine to now, after investigation, Li went to Madeleine's house to extort money, and after getting the money, he went to Mexico to hide from the limelight. Madeleine followed him, put on makeup and killed him (written by the novel), and finally the ending of the story, as you can see. The real murderer was Madeleine's biological father, who brought Dahlia home. Madeleine's mother found out and killed it. Together with the old man, she got the appearance of the body at the beginning. I have to say here that she didn't kiss the old Madeleine, but the one I mentioned. These two people used to be business partners. The old man had an affair with Ma's mother and finally gave birth to Ma's adoptive father, which was not a good fruit. He took the business for himself and crippled the old man. This is why Li was able to blackmail successfully (but he didn't know the details, only knew that it was related to Madeleine's family)