Had me popping out of my chair for the last 20 minutes, and gets 4 stars pretty much for the train sequence alone.
Somewhat flabbergasted by this. What stood out most was how neutral the film was considering where it goes. The obsessive nature of the case, having to go over the same ground over and over again, mixed with the deathly interiors of the offices and hallways makes everyone a ghost like figure. The sound in this is incredible; the silences cuts deep, settling inside you. Really creeped me out.