I don't know about the reviewer above who gave this movie 3 stars and complains about a lot of the things in the movie. This was either the best or second best movie out of Hong Kong in 2007. It was definitely the best role I have seen Andy Lau in in a long time. Also, it is the best acting I have ever seen from Louis Koo. Anita Yuen's short role was very well executed as well. JingChu Zhang was excellent as well.
I really don't see any faults in this movie that I can remember. Maybe the reviewer above who gave it only 3 stars has never met someone addicted on hard drugs before, but trust me - they are usually a mess. Louis Koo played it very well I thought. Everyone should see this movie if they get the chance. It is interesting, intriguing, and definitely never boring.
