Happily, my second run-in with the Romanian New Wave at the 46th Chicago International Film Festival was a great deal more successful than my first. The fourth film from writer-director Radu Muntean - though the first given even the remotest push amongst we English-speakers - Tuesday, After Christmas is not at the tip-top of the country's output, but it is awfully wonderful in a great many ways, a character study of uncommon penetration and honesty.

I made a perfectly terrible mistake, however, in reading the Siren's exquisite consideration of the film's reception broken down along gender lines, and I'm having a profoundly difficult time getting started, because I am feeling unpleasantly male right at the moment (also, I'm now aware that nothing I say about the film is going to be within swiping distance of "original", plus I'm terrified about accidentally plagiarising somebody. This, kids, is why movie critics shouldn't read other movie critics). But here goes, anyway:

The film opens in grand New Wave style, with a take that must be every bit of seven or eight minutes long. Two people are in bed: Paul (Mimi Brănescu), a pudgy man, unattractive without being outright ugly, and Raluca (Maria Popistaşu), a much younger woman, pretty in the manner of a normal human being and not a movie star. They're both completely nude, cuddling in obviously post-coital satisfaction, and they talk about a great many things: Paul's smoking habit, his genitalia, his wife. Yes indeed, Paul is cheating with the lovely Raluca, and the consequences of that fact will be explored in sometimes unbearably direct ways over the film's 99 minutes.

For right now, though, I want to hang on to that opening scene: not dirty, not erotic, nor squeamishly anti-erotic, it is one of the most blandly casual depictions of nudity I can think of ever having seen in a movie, two people who are mostly comfortable with their bodies and each other not making a big deal about the fact they just had sex and haven't dressed yet (though Paul, doubtlessly aware that the young woman is out of his league, is noticeably less comfortable, which is probably why he awkwardly shifts the conversation to give her a chance to reassure him that he's sufficiently endowed for her needs). As Tuesday, After Christmas is primarily a naturalist film, observing the human animal with as little editorial interference as it can manage, this opening is just about the best set-up possible: the instantaneous nudity is distracting and quickly ignored, training us to spend more time paying attention to how these characters exist in reference to each other, what they express and do not express. The quick acquisition of this skill is a great necessity in following along what happens next, as Paul and his not at all younger, not tremendously pretty wife Adriana (Mirela Oprişor) go Christmas shopping for their daughter, as Paul takes this same daughter, Mara (Saşa Paul-Szel), to her orthodontist - whom we already know to be Raluca - and as he decides that he is more in love with Raluca than his wife, and he's going to end his marriage to be with his mistress.

Muntean's treatment of all this material is brilliantly uninflected: virtually every scene takes place in a single shot, which is left as neutral as possible. No dramatic lighting, very little in the way of pushy focal tricks. It is a fiction film done strictly as actuality (though, of course, this very distinct lack of visual editorial, as well as the comprehensive and tremendously evocative mise en scène is altogether artificial, and there is the nasty trick of it all). We have, in effect, nothing to pay attention to except the characters and the immaculate performances that bring them to life.

The film is embarrassingly rich; as each scene contains its own little drama, expressed in a single merciless take, it's rather like watching a collection of tiny plays, all of them painfully effective. It can be a thriller, as when Paul brings Mara to Raluca's office, to find Adriana waiting for them: an amazing depiction of the four characters, ranging from Paul's puffy nervousness to Raluca's tight professionalism masking deep irritation at both her lover and her rival (this scene is Popistaşu's absolute best moment in the film), with Adriana's bland practicality suggesting just what it is about her that Paul finds so dull, even as we must all agree that she is behaving exactly as a normal adult ought to. And Mara, in her infinite innocence (she acts much younger than her age) is the unwitting victim of all of it, a heartbreaking linchpin for the rest of the drama. It can be a black comedy, as when Paul sits waiting with Raluca's mother, whose righteous hatred of the man about to ruin her daughter's life couldn't be more obvious if she tore his throat out with her teeth.

And in its triumphant moment, it is shattering beyond all but the very best infidelity dramas. Paul tells Adriana everything, as he must, and her subsequent explosion features some of the best screen acting I have seen in many a long month (Brănescu and Oprişor are married, which perhaps explains some of the peerless intensity and depth of the performances). Paul seems genuinely befuddled that his wife is hurt at all; it is probably the first time that this sad, pathetic middle-aged shell has realised that his actions effect other people. Adriana, for her part, lashes out with a scorched-earth tirade that offers him no quarter, no pity; she cuts him open and lays bare his brainless selfishness with direct simplicity, no Oscar-clip theatrics but just the cold fury of a woman whose life just broke into a million pieces. It is profound, cinema at its most staggering.

At this moment, the balance of the film tips, I think: it has previously been a study of three people with emphasis on an understandable if not particularly likable or sympathetic adulterer, and hereafter it is the tragedy of a deeply blinded, greedy man - still understandable, but now quite impossible to like - and the particular story of a woman recovering from the cruelest blow she will ever receive. Once the film becomes about the death rattle of the marriage, Raluca never returns: and while the film never becomes a strict two-hander, it's hard not to focus on it entirely as the interplay of two personalities, one suddenly aware of his own foolishness, the other building a great steel wall between herself and the world. It is a great achievement, right up to its sudden but perfect ending (the film could hardly stop on more impeccably-timed frame), and while it is maybe not so incredible an aesthetic achievement as the movement's leading lights, such as 12:08 East of Bucharest (a film that is name-checked in Tuesday, After Christmas) or 4 Months, 3 Weeks and 2 Days, that is only because it is in the film's simplicity that it delves into such crushing emotions.