A Ma Soeur! **
Dir: Catherine Breillat
With: Anaïs Reboux, Roxane Mesquida, Libero de Rienzo, Arsinée Khanjian, Romain Goupil, Laura Betti, Albert Goldberg, Odette Barrière
93 mins, cert 18
www.amasoeur.com

With a curious pedantry, an insistent directorial stare, Catherine Breillat has got back on to the subject of sex - sex degree zero, sex estranged, though not entirely divorced, from a recognisable context of cause and effect. It is a film that looks like it's going to be a sentimental summer romance. A plain, plump, introverted 12-year-old girl watches appalled and fascinated as her beautiful 15-year-old sister has her first sexual experience with an Italian boy they meet on holiday.

And, after a while, just as we are beginning to know and like the characters, Breillat shatters their lives, and our anticipatory involvement in them, with a great arbitrary swipe of violence. It is a shocking but empty gesture from this important director - which Breillat presents as somehow a necessary corollary of the ideas about sex she raised before the catastrophic finale is dumped on us from such a height.

Anaïs Reboux is Anaïs, the younger sibling who is continually and querulously asking the lovely Elena (Roxane Mesquida) about love and sex. Elena insists that she only wants to surrender her virginity to someone she really loves. Anaïs is nettled by Elena's airy implication that, for someone as pretty as her, it will be a seller's market. So, with sullen bravado, Anaïs says she wants to get it out of the way with someone she doesn't care about.

Into this dispute steps Fernando, preeningly handsome and Italian, a few years older than them both. He is sitting in a cafe when Anaïs and Elena arrive and he suavely invites them to join him. Then Breillat contrives what is a very funny and, in a way, amazing scene. Elena and Fernando flirt "reasonably mildly" but then he takes her hand, fingers interlocking, and they start to kiss, all within about a minute of meeting, entirely unselfconsciously, while Anaïs just looks on.

She effectively becomes the chaperone for the young lovers as they go for walks in the woods or on the beach, and so combines voyeurism with an autistic withdrawal into herself. Anaïs Reboux gives a lovely performance as the discarded sibling, singing and mumbling little songs to herself and living in her own world.

Anaïs swims around a lot in the pool, kissing first the diving board and then the steps, as pretend lovers. All this leads to the candid and wince-makingly plausible scene in which Fernando attempts to have illicit sex with Elena in her single bed, while at the other corner of the room Anaïs is required to be, or at least pretend to be, asleep.

The sex scene, and many other scenes, are conceived by Breillat in the form of extremely long, unhurried takes, and she is brilliant at conveying the sheer boredom of being a teenager as well as the erotic rapture.

But where is it all leading? The answer appears at first to be: an interesting dissection of their parents' lives. As she discovers Elena's under-age sex, her mother erupts with rage, abandoning her liberalism entirely, and glowers not just at her, but at her workaholic husband, who has left the holiday to get back to the office, leaving tough parental responsibility to her.

If we thought that these real, recognisable human consequences were the point, however, we were quite wrong. Because it is here that Breillat launches her bizarre violent denouement, quite out of left field, just before the credits: an event which has all the dramatic and cinematic credibility of a Crimewatch reconstruction. And what is more disappointing is that Breillat, with some effrontery, appears to suggest that this event, and Anaïs's reaction to it, is a cogent ending: providing a darkly satiric response to Elena's bourgeois yearnings for romance. There is something worrying about Breillat' s final scene: the implication that a vivid unanswerable reality about sex has intruded at last.

The effect of this grotesque eruption following what had been a very well- observed and well-acted human drama is baffling. Even if it is read as an imaginary event in Anaïs's mind it is almost outrageously unconvincing and unsatisfactory, and the lingering suggestion that the violence has in some sense grown out of the preceding events is strange. Looking back on the plot from this new perspective, it is possible to endow the girls' fragile lives with pathos. But it is as if Breillat, the creator possessed of what Greene called the sliver of ice in the heart, has been eyeing them with cold and enigmatic scorn all along, ready to send down her thunderbolt from the blue.

Breillat is such a distinctive director and, in her previous film Romance, her candour about sex, and darkly playful approach to its madness and pain was compelling because of its vital components of humanity and wit.

Here she has mysteriously subtracted these elements - and A Ma Soeur, though possessed of moments of power, is a minor Breillat film that leaves a strange taste in the mouth.