The score, composed by David Hung, perfectly complements the on-screen action, elevating the emotional impact of key scenes. The editing is seamless, with a narrative that flows effortlessly from one scene to the next.
The film takes place immediately after the events of the second film. The story revolves around Chan Wing-yan (Tony Leung) and Lau Kin-ming (Andy Lau), two undercover police officers who have switched roles. Chan is now working for the police, while Lau is working for the triads. Infernal Affairs III