Changeling, Clint Eastwood, 142 mins, 15<br>Four Christmases, Seth Gordon, 88 mins, 12A

Clint Eastwood's new film is based on a true story, but it's the definition of "stranger than fiction". Set in Los Angeles in 1928, Changeling stars Angelina Jolie as Christine Collins, a lone mother whose nine-year-old son, Walter, vanishes from home one afternoon while she's at work.

The police grudgingly investigate, and five months later they inform Collins that Walter has been found alive. But the boy they present to her is three inches shorter than her son. When Collins demands that the investigation be resumed, with the backing of John Malkovich's campaigning priest, the LAPD's answer is to denounce her as an unstable, unfit mother.

It's a tale that takes the horror of a child's disappearance, combines it with the discomfort of having a cuckoo in the nest, and then adds the chilling revelation that there's a serial killer loose who preys on small boys. It should make for a dark, disturbing nerve-jangler – so it's strange that Changeling leaves you so unmoved. Staged by the 78-year-old Eastwood with all the style and atmosphere of an afternoon TV movie, it's one of those phoney-looking period dramas in which every vintage car is polished to a shine and every last actor is wearing a brand new outfit from the same designer. The remarkable story plods from A to B, with functional dialogue and non-existent character development: the heroes are all purer than pure; and the villains couldn't be more hissable if they twirled moustaches. Even the supposedly crusading heroine is just an Anxious Mother, straight from central casting. You can never forget you're watching an A-list star emoting for the camera, so when she's screeching "I want my son", it might as well be "I want my Oscar!".

Most of us assumed that last year's Fred Claus would be the worst Vince Vaughn Christmas film ever made, but just 12 months later, we have the abortive Four Christmases, which limps along unfunnily for a scant 80 minutes. Vaughn stars alongside Reese Witherspoon as a couple who have agreed never to get married or have children. Naturally, Hollywood cannot permit such a deviant lifestyle choice, so our heroes must learn the importance of family. The perverse thing is, they learn it by spending Christmas with four sets of fantastically toxic relatives, an experience that would drive any sane man to book a Boxing Day appointment at the vasectomy clinic.

Also showing 30/11/2008

What Just Happened (102 mins, 15)

Barry Levinson directs Robert De Niro, pictured right, in a moody comedy drama about a harassed Hollywood producer who's trying to keep his two ex-wives happy while convincing Bruce Willis to shave off his Santa beard for an action-hero role, and convincing a punky British director to re-edit his thriller so it doesn't end with a dog being shot. There are some scandalous anecdotes and barbed one-liners, but that's all the film is: anecdotes and one-liners. Not so much "What Just Happened" as "So What?"

Flawless (105 mins, 12A)

Doddery British heist movie set in 1960. Demi Moore, with a Princess Margaret hairdo, stars as a diamond company executive who's the wrong gender to get the promotion she deserves. Michael Caine co-stars as a lowly janitor who has a plan to help her get her own back. It could be the least clever plan in the history of the genre.

Ano Una (78 mins, 15)

The whole of 'Ano Una' is a montage of still photographs, with voiceovers divulging the characters' thoughts. It's an interesting technique, and a lot more interesting than the story of a neurotic American student on holiday in Mexico, and the teenage local who has a crush on her.