I remember watching this movie in the theater many years ago!
The setup was interesting. The cast was amazing and it all seemed so riveting, between the dialogues and the mystery everything was working very well.

The movie failed, for me, the moment they introduced that character you were alluding to towards the end. The pacing, the atmosphere.. everything shifted once the tension started resolving and by the end of it I was a bit disappointed.

It was stylish and entertaining enough to watch but didn't work well as a whole.