Build a movie plot around this: What does Lau use to determine the code of Yeung's office safe? spy cameras
Answer:
Infernal Affairs III uses parallel storytelling, flashing between the past and the present.Five months before Yan's deathYan (Tony Leung Chiu Wai) seeks to uncover the link between Triad boss Sam (Eric Tsang) and the mysterious mainland triad boss Shen (Chen Daoming). Since Sam's ascension to the seat of triad lord was due to Ngai's (Francis Ng) death (see second film), Sam is suspicious of all those who followed him in the past. He tests Yan's loyalty by asking him to smash an ashtray on Shen's follower during a negotiation, resulting in Yan being arrested by Inspector Yeung (Leon Lai Ming). After being released, Shen smashes a bottle of liquor on Yan's head and called truce between his gang and Sam's gang.At the same time, Yan is prosecuted by the police for violent behavior. His superior Wong (Anthony Wong Chau Sung) manages to persuade the court to allow Yan to go and see a psychologist instead of being sentenced to prison. Thus we are shown how he met Dr. Lee (Kelly Chen) regularly for psychological therapy. The two subsequently begins a romantic relationship.Later, Sam asks Yan to deliver illegal arms to Shen but he himself and other members of the gang did not turn up. Yan delivers the cargo but Shen's gang discovers it is just empty boxes and both gangs begins firing gunshots at each other. Shen and Yan shoot each other in the battle, but both aim at the limbs. Shen thus discovers that Yan is a cop just as Yeung arrives at the scene. Yeung then tells Yan that Shen is not Shen (but actually an undercover cop from the mainland). Yeung also tells Yan that it was due to Yan leaving the police cadets that he gained top honours, thus revealing that Yeung knew Yan is a cop. The three shake hands and wait for the mayhem to die down before returning to their bases.Ten months after the events of Infernal AffairsFormer Triad mole turned top cop Lau Kin Ming (Andy Lau) has been demoted to administrative duty pending the investigation of his involvement in the death of Yan and Billy (Gordon Lam Ka Tung). In a...