Following the success of "Infernal Affairs," there have been many films imitating but often failing in duplicating the movie in terms of box office success, script, acting ability, etc. This one delivers . . . kinda. The same problems I had with "Infernal Affairs" are still present in this film.
The story is complicated, but aren't they all? Shawn Yu plays "Fat," an orphan raised by his "Uncle Chai." Uncle Chai is a follower of Brother Dragon, who is played convincingly by Eric Tsang. And the movie follows them through a period of a year or so, where everything important seems to happen. Tsang is a very good actor in my opinion. His diminutive frame precedes and almost underestimates him. However, like in this film, and the other films that I've seen with him in it, he often steals the scenes, and is able to switch from "menacing" to "sympathetic" effortlessly and without seeming contrived.
The film in itself is more violent than your average HK crime/drama, although in some areas, it pussyfoots around where an unflinching camera shot would have been very effective. The twist ending is believable and very well-written.
The flaws of this film include Tsang's eyebrows (You'll know what I mean), Yue's inability to enunciate his words made for listening to the dialogue a chore, crappy acting and stereotypical roles by the female leads that almost made them unbelievable, and underestimated their execution. It may seem like there are many flaws. However, the main focus is not in their romantic lives. So other than that, I thoroughly enjoyed this film.