When Hollywood does disabled it's seldom a pretty sight - remember Sean Penn in the ickiness overload that was I Am Sam?

So it's particularly pleasant to report that Sigourney Weaver's portrayal of an autistic mother is never cringe inducing but utterly compelling.

She plays Linda, a high-functioning autistic woman with a determinedly literate view of the world and a tidiness obsession.

When taciturn Englishman Alex turns up at her door to confess he was driving the car in which her 19-year-old daughter Vivienne was killed, she treats the announcement with a disarming matter-of-factness.

Inviting him in, her clinically logical pragmatism dictates that he stays at her house until the bin men come the following week (Linda hates dirt so Vivienne used put the trash out).

Alex, who is just released from prison, is bulldozed into submission and so begins an utterly charming relationship between the practical mom and the hesitant stranger.

He also strikes up a rapport with Linda's neighbour (Moss), a divorcee who is intrigued by the surreal predicament the Englishman finds himself in.

Director Marc Evans made his name with the thrillers My Little Eye and Trauma but here he magnificently changes tack to produce a scintillating relationship movie like no other.

Will Weaver is fine, Rickman is simply astonishing, delivery wry lines of dialogue and conveying the anguish of guilt without resorting once to the grand gesture.

The odd-couple routine with Weaver, is winningly played, the highlight being a game of Scrabble where spelling is of minor importance.

Hampshire - in a brief appearance as the doomed Vivienne - uses her limited screen time to impress with a spiky display of teenage exuberance.

Poignant and painfully funny, grab yourself a slice.

Tim Evans