While this is a great film with an incomparable score and outstanding cinematography, it leaves a lot to be desired.
It is really not necessary as the first two films really give us all we need. It is light on action and heavy on psychological trauma. Andy Lau as Inspector Lau has taken care of all the moles - or he thinks he has. he is not sure and wants to be clear there is nothing tying him to Sam so he can be the good cop he wants to be. SP Leung is a creepy fellow and we are never sure just what he is. Is he a mole, or just a crooked cop. It is never clear.
I was glad that Kelly Chen got a much bigger role as Dr. lee, but it would have been even better if we saw a relationship with Yan. It was obvious that she had love for him, but it never blossomed on screen. Yes, I know that would be a violation of the doctor-patient relationship, but it was there under the surface. Why didn't it come out.
We got to see quite a bit of Tony Leung in this film, and that is always a good thing.
It was very distracting the way the film jumped back and forth through time. It was trying to tie up the loose ends, but it was disconcerting.
It could have been an outstanding film, but it'll just have to be great to see the actors and enjoy their performance.