Lars and the Real Girl, (12A)

Shy young man brings home his ideal woman – and she's an anatomically correct plastic doll! The premise shrieks indie quirkiness, and the opportunities for smutty humour abound; but as it turns out, Lars and the Real Girl is a humane, and often sweet, study of the strain of growing up and having adult relationships. Why, at times it's almost plausible.

That it works at all is largely due to an intelligent script by Nancy Oliver (one of the writers of Six Feet Under), who resists the urge to schematise Lars's delusions, instead sketching in a background of emotional deprivation that makes sense of his inability to cope with a real, live woman. Craig Gillespie directs at a nice, leisurely pace and gets some excellent performances, particularly from Patricia Clarkson as the severe, yet kindly doctor who advises going along with the delusion, and Emily Mortimer, uncharacteristically adorable as Lars's needy sister-in-law.

Ryan Gosling, playing Lars, starts weakly – his principal way of indicating the character's difficulty with other people is blinking a lot – but does much better later, when he has some full-blown neurosis to play with. What strains credibility is not his relationship with "Bianca", but the attitude of his neighbours and colleagues: instead of shunning him as a pervert and potential serial killer, they rally round as one, gamely resisting the urge to gawp or criticise. Even the girl in the church choir with a crush on him isn't put off – because, what, his fidelity to a plastic doll shows he's a guy you could rely on? And I could have done without the bit when Lars reads Bianca to sleep with Don Quixote – that self-consciousness poking through. All in all, though, the week's most pleasant surprise.