Film review: In the House - It starts like early Michael Haneke, but finishes like late Woody Allen

Kristin Scott Thomas and Fabrice Luchini become party to a guilty secret in In The House

François Ozon's tantalising new comedy, In the House, is all about storytelling, and that's something it does delightfully well – to begin with, anyway. Fabrice Luchini stars as a prissy middle-aged teacher of creative writing at the French equivalent of a modern comprehensive. He has resigned himself to being bored to tears by his pupils' semi-literate compositions, but one evening he reads an essay that sends his eyebrows rocketing above his owlish spectacles. Its writer is a 16-year-old (Ernst Umhauer) who has inveigled his way into a classmate's home in order to spy on and satirise his enviable life. The teacher and his wife, Kristin Scott Thomas, are appalled by the voyeurism – but not so appalled that they aren't salivating for the next chapter. Soon, Luchini is breaking school rules to ensure that the boys maintain their friendship, and advising the protégé on how to improve his subsequent undercover dispatches.

It's a brilliant premise. For a start, it offers us a deliciously sinister cuckoo-in-the-nest thriller. But it also offers us the pleasure of seeing Luchini and Scott Thomas mirror our own guiltily titillated reactions. On top of that, there are the self-reflexive scenes of the teacher criticising his pupil's prose, so we, in turn, get some lessons in writing and rewriting. And then there's the mystery of whether the essays are all true, or whether both the teacher and the viewer are being taken for a ride. Phew. It's like Funny Games, except more funny and more of a game. After half an hour, I was rubbing my hands and asking where on earth Ozon would take us next.

The answer, I'm afraid, is nowhere in particular. Umhauer's delicate, angel-devil beauty is enough to suggest that he could wreck lives with a bat of an eyelid, but in the event he's disappointingly well-behaved, at least by the standards of teenage boys. Ozon's allusions to class divisions and the teacher's own frustrated literary ambitions come to nothing, while a comic sub-plot about Scott Thomas's travails as an art gallery manager has precious little to do with the central narrative.

In the House is always diverting, but it becomes more like one of the light, slight strands of a recent Woody Allen film than the devastating mind-bender it might have been. In its last half-hour, Luchini keeps telling his pupil that his story needs a better ending. Most viewers will be thinking much the same.

Another example of a film that doesn't quite reach its potential, Good Vibrations (Lisa Barros D'Sa & Glenn Leyburn, 103 mins, 15 **) is an amiable, irreverent biopic of Terri Hooley (Richard Dormer), the record-shop owner who nurtured the Belfast punk scene. Dormer is a decade too old for the part, but he certainly has the gnome-ish charm that seems to have been Hooley's defining feature. Determined to have nothing to do with either the Loyalists or the Republicans, he sweet-talks some paramilitaries into letting him set up his record shop. "There's to be no trying to kill me," he chides. At this point, Good Vibrations looks set to be a more political – and noisier – answer to The Commitments.

It isn't. Hooley goes on to discover the Undertones, among other bands, but Good Vibrations doesn't get around to establishing who the musicians are, or what their songs mean to them. Indeed, it doesn't establish what punk means to anyone in Belfast, so we're left to conclude that it's the tinpot hobby of a feckless eejit who doesn't deserve his long-suffering wife (Jodie Whittaker). More than anything, what's lacking from Good Vibrations is punk rock's adrenalin and drive. Someone needed to turn up the volume.