It's a shame, that when it finally builds an impressive momentum near the end, your sympathy with the elusive protagonist is gone. The reason for the first is, that apart from being terribly well-written, it's also a constructed in an unseen fashion, which at first is bit baffling, but ends up leaving you stunned - in a "blown away" kind of way. Kassowitz could have brought more to the role, I guess - and if he had, this might have been a cinematic revelation.