The things kids do, eh? You turn your back for one just one minute. Next thing you know, they're being videotaped having gay sex with a nightclub manager and getting you embroiled in a $50,000 blackmail scam. Who'd have 'em?

When Lake Tahoe housewife Margaret Hall (Tilda Swinton) finds her son Beau's boyfriend dead on the shoreline one morning, her parental instincts kick in and she hides the body to protect the kid. Mistake.

Pretty soon would-be blackmailer Alek (Goran Visnjic) is at her door waving the videotape and demanding cash to keep it from the cops.

But Margaret doesn't have the cash. And when Alek's boss Charlie - a man with all the compassion of a CIA-trained polecat - arrives on the scene, her first impetuous act plays out into a bloody ending.

The Deep End picked up plaudits on this year's festival circuit, with a Best Cinematography gong at Sundance and an Official Selection placing in Cannes.

And it's the kind of film that festival audiences love, a movie with faith in its own potential. Derek Jarman muse Swinton holds the centre with a masterful study in quiet desperation, preserving a fragile outward calm as her private world is turned inside out. The cinematography of Giles Nuttgens captures every freezing detail of Lake Tahoe's cold, clear water and crisp blue mountain skies.

So as a study in suburban isolation, with Swinton holding the domestic fort amid demanding adolescents, aggrieved silences, neglected housework, and unasked for responsibilities, The Deep End excels.

But as a suspense thriller it doesn't really make the grade. The film's portrayal of a powerless woman dragged along by the tide of events doesn't lend itself to edge of the seat plot twists. What's more, blackmailer Alek's compassion for his intended victim is obvious from the moment he steps onto the set, and renders the rest of the film more or less predictable.

And as trumpet-playing prodigy Beau, Jonathan Tucker does nothing to convince as a catalyst of disaster. He's so limp, with teary doe eyes and a constantly trembling lip, that it's almost impossible to see what nasty lover Darby ever saw in him. Unless, of course, he had a thing for compliant virgins.

That'll be it, then.