Great stuff, a really tense, effective thriller. McGregor and Williams are both excellent, though I guessed the twist, or at least the general gist of it, about halfway through. Also Polanski doesn't exactly show a great aptitude for portraying politics, and the attempts to fake the US are clunky to say the least. Other than that I really enjoyed it. Oh, and try not to see the American version as I did, with all the ridiculous bowdlerised swearing. It's really, really bad.