The portrait of a 17 years-old girl, in 4 seasons and 4 songs.

A vague, joyless account of the seasons of sexuality.

We first glimpse the 17-year-old Isabelle (Marine Vacth) through her little brother’s spying binoculars. She’s lying on a pebbly French beach with her breasts bared to the sun – a pretty, starved-looking girl who could pass for much younger. Walking down to the sand, the boy (Fantin Ravat) plays shadow puppets on her browning skin, teasing her about boys and sex and wanting her sisterly advice. But she’s about to go on a journey that he cannot follow.

Later that day, Isabelle will sneak out of her family’s holiday house and lose her virginity, perfunctorily, to a German tourist. When she gets back to Paris, she’ll secretly start working as a prostitute after school, meeting men who are old and wrinkly enough to be her grandfather. Why does she do it? Certainly not for the money, which she stashes haphazardly in a laundry cupboard. And if her listless affect is anything to go by, the sex is not giving her much pleasure either, though there is one older gentleman (Johan Leysen) she seems to connect with as he becomes her regular client.

When Isabelle is eventually found out and questioned, she has no answers for the police, or for the psychologist, or for her distraught mother (Géraldine Pailhas), who understandably wonders where she’s gone wrong as a parent. Isabelle’s motivation is a mystery, even to herself. And while this may be a valid comment on the inscrutability of dangerous teen behaviour, unfortunately it doesn’t make for interesting viewing in a film that invites us to look, but not to understand.

At his best, French writer-director François Ozon is capable of delighting us with his polished style and cheeky humour. (Think of his short films like the gorgeous A Summer Dress and the colourful farce of 8 Women.) Ozon has also proven adept at creating unnerving mysteries around identity, sex and love, as with See the Sea, Swimming Pool, Under the Sand and the incredibly moving and poignant 5x2. But with this latest work, which was bafflingly nominated for the Palme d’Or at Cannes last year, Ozon seems too lost in the surly surfaces of his vacuous young subject to come up with a proper plot or motivation for the action, let alone a sense of wit or whimsy.

The film is divided into four parts that chart the passing of the year in Isabelle’s life – Summer, Autumn, Winter and Spring – each of them containing a pop song by French chanteuse Françoise Hardy, which fail to illuminate the plight or mood of the character. There are intriguing hints of family melodrama – is Isabelle’s mother having an affair with her best friend’s husband? Is there impropriety with her stepfather? – but none of it goes anywhere.

The steady eye of the camera certainly seems in love with Vacth. Shot crisply by DOP Pascal Marti, and edited with unobtrusive fluidity by Laure Gardett, the film certainly looks good. Lingering on the young woman’s full lips, her silky long hair and the knobbly ribs in her arched back, we’re left feeling uncomfortable. Why are we looking at her and what are we watching this for? At least the title is honest in its appeal to voyeurism, for there’s little else to be had on this joyless journey.