If Roman Polanski never makes another film after The Ghost Writer, the very least we'll be able to say about the man is this: he managed to end his career with a pretty crackerjack thriller, no masterpiece on the scale of Chinatown or Knife in the Water (and really, how could it be?), but a smart, tight picture that looks just nifty and goes down as smooth as a glass of the nicely aged whisky enjoyed at intervals by the film's protagonist.

That fellow, played by Ewan McGregor in what feels like his first credible screen performance in ages, is an unnamed writer who has found a nice degree of success in ghost writing the memoirs of famous people who don't have the talent to do it themselves. He's being called upon to provide his services, in this case, for a disgraced former Prime Minister of Great Britain, a Tony Blair stand-in named Adam Lang (Pierce Brosnan) who is currently in a spot of worry about whether he misused his powers to imprison British nationals suspected of terrorism. That's not our author's chief problem, though; he's a bit more concerned about the drowning death of his predecessor, either an accident or a suicide unless - brace yourself - it's not actually either.

Going any further into the plot would be pointless: not for fear of spoiling anything, but just because there's so very much plot, which reveals in layers the degree to which Lang's government was in bed with the CIA, pulling various shenanigans over on the British people. Besides, the exact details of the plot aren't necessarily the point of the movie, although God knows Polanski (who co-wrote the screenplay with Robert Harris, from Harris's 2007 novel) takes no small pleasure in working us through every twist of the narrative. The story is rather about the creation of a wall of paranoia, where the question of "What happened?" is devoured by the protagonist's increasing awareness that whatever happened, he's gotten himself mired in something dreadful, and his investigation to find the answers is less about the truth and justice, and more about his own survival. A rather quintessential Polanski thriller, basically, and one of the best paranoia movies in the last several year - it recalls the masterpieces of that subgenre from the 1970s, though it is altogether modern in execution.

That said, it doesn't do to complete toss the specific details of the narrative out the window: it manages to incorporate modern political concerns into its fabric rather neatly, and even manages to sneak a certain degree of self-reflexivity into the proceedings, when we learn that Lang can't leave the United States without risking extradition (that he is stuck in the one country in the world that Polanski had to avoid is a touch of coy irony). The political commentary is hardly hidden - at one point, characters discuss the fact that the U.S. is alone among Western countries in refusing to recognise the International Criminal Court, but enjoys the company of China and Iraq - but then, it's something of a blind side against Blair, not a witty drawing room satire. Although it should be said that one of the few major flaws with the film is that all of this political content is used as the pretext for the narrative, but little or nothing further is done with it: in 2004, it might have been a bold statement to indict Blair for being a U.S. stooge, but in 2010 it's very much less impressive, and last year's In the Loop, to name one example, managed to get a lot more mileage out of the simple observation that the British government became a sock puppet in the War on Terror.

Conceding that, the film resting on that base is an awfully good thriller: the pacing is swift (Hervé de Luze's editing is unimpeachable), and Polanski keeps the paranoid feeling coming without pause, with special mention made for a really top-notch car chase. The cinematography, by the uneven Pawel Edelman, maybe errs on the side of over-the-top theatrics (this is a very dark, very grey film), but something about the visual bombast suits the mood of the film rather nicely, and it also matches well with the house where most of the action takes place, a harshly modernist affair of glass walls and dysfunctional design elements (giant metal slabs for the stairs! wooden bathtubs!). While all this gives The Ghost Writer a relentless, and somewhat grim feeling, there are plenty of cynical jabs in the script and in the visuals that remind us, more than anything else, that this is a Polanski film. I also have to praise the score composed by Alexandre Desplat (one of the living treasures of cinema, and even so this is his best work in a number of years), a marvelous blend of the expected thudding baselines of a thriller, with weirdly orchestrated counter-melodies that give the soundtrack a certain... I am tempted to say "carnivalesque" tone, but that's missing the mark. Let us just say, the score is equally as cynical and sarcastic as the screenplay can be, and I might go so far as the call the score the single most important element of the film.

As the humans inside of all this, the cast is mostly very good: McGregor I have already mentioned, but let me do so again, suggesting that he plays the role of a professionally anonymous man stricken with confusion and fear rather perfectly, and mention also that Brosnan is outstandingly well-cast as a slick, empty politician. The sinfully under-used Olivia Williams is brilliant as Lang's worn-out, ignored wife, and certain other people (Eli Wallach especially) are great in small roles that would be spoilery even just to describe them. The only weak link is Kim Cattrall as Lang's personal assistant: she stomps on her lines instead of reading them, her accent goes all over the place, and she makes it generally impossible to guess at what her character is feeling. But no matter.

This is a nasty, fun ride, and while the ultimate reveal of everything that's going on is decidedly lame (it smacks of the storyteller realising that he needed to resolve everything quickly, and doing so with a wow finish that doesn't actually tell us all that much of anything; though as twist endings go, it is a surpassing honest one, with two huge clues planted in plain sight earlier in the film in such a way that you are almost guaranteed to overlook them), getting to that point is a really outstanding bit of genre filmmaking - it is indeed thrilling, and amusing besides. Glossy craftsmanship, sure, but Polanski is, whatever his personal failings, a terrifically talented man, and when he decides to give you a good jolt, you know that you've been jolted. Especially in the final shot, which no other filmmaker could ever have created, and which is so blindingly perfect that it leaves you convinced, as you walk out of the theater, that you just saw a masterpiece. It's not; but I said that, didn't I? Well, whatever. It's incredibly successful at the particular thing it sets out to do, and that's all we should ever ask of any movie.