This is a movie that could be a promising mystery/thriller, and does have a capable director and a reasonable cast. However the story itself was so bad that I have no idea how it was even made into a movie.
Just to name a few things that are sorely lacking in this movie without spoiler:
1. No mystery was really solved in this movie.
2. The mystery was not really even developed that much in this movie.
3. How the hero succeeded was nothing short of miracle - multiple miracles in fact. Things that happened really don't make sense in reality.
I could go on to details of which plot holes/coincidences are too incredible but I'd rather not spoil the plot. Suffice to say that there're plenty.
Simply put, if you're looking for a decent mystery/thriller movie, this is NOT it.