Having not read the book and not knowing anything about the story, I was completely immersed in the ambience of this film. It was immediately reminiscent of the work of the late, great Stanley Kubrick. Even some of the cinematography reminded me of 'The Shining.' But it wasn't derivative. The acting was first rate and subtle. Tensions moved just below the surface with all of the supporting cast. Mr. DiCaprio performance gave us an excellent look into the paranoia that comes from living with the past and what could have been. I did not see the ending coming, but suspected something was amiss very early on. I love Martin Scorsese and would love to see him venture into this genre again. This movie is a definite 'must see.'