It's entirely possible that sending the audience out feeling lousy was intentional

it is finally so absorbing because it plays like a lyrical road odyssey that’s also a detective story.

At first rather annoying in its heavy emphasis on reenactments, this movie ultimately proves fascinating, simply because the complicated, highly dramatic tale it tells still almost defies belief.

While it is a pity that the story wasn't told with more visual finesse, this is trivial compared to our real-world problems. It takes a good movie to put that into perspective.