Dir: Paul Haggis. 2007. 120 mins.

The really fascinating aspect of aul Haggis's follow-up to the Oscar-winning Crash is the way it uses Hollywood conventions as a Trojan horse to deliver a radical, anti-war message to a mainstream audience.

Like Brian de Palma's passionate cinematic 'j'accuse', Redacted, which also screened in Venice, In the Valley of Elah looks at the way the war in Iraq brutalises the young American soldiers who serve there.

But whereas De Palma confronts his audience, Ken-Loach-style, with his uncompromising, heart-on-sleeve version of an alleged war crime, Haggis is more subtle.

Elah is a denunciation of a dirty war disguised, for much of its length, as a murder mystery about the killing of a US soldier, newly returned from a tour of duty in Iraq.

And it's a murder mystery that comes complete with those stock figures - the stubborn family member determined to uncover the truth about the crime, and the police officer forced to fight against bigotted superiors and a personal crisis of confidence in order to solve the case.

The challenge of this approach, of course, it that more demanding viewers may be alienated by the sheer conventionality of that Trojan horse casing, before the film starts to reveal its true colours in the final stretch.

Two things make the journey worthwhile, for all but a few misjudged moments. The first is Haggis' sure, nuanced command of story structure, his ear for naturalistic dialogue, and his eye for resonant detail.

The second is the performance of Tommy Lee Jones as Hank Deerfield, the gruff, old- fashioned military father of murdered soldier Mike Deerfield.

Handed the gift of a role by Haggis, Jones turns it into one of the highlights of his career so far, and it's difficult to imagine him not being among the five Best Actor nominees when awards season comes around.

Elah (the reference is to the valley where David slew Goliath) combines genre appeal with news value, and should turn into a solid domestic performer across a wide demographic.

And although it's tussling with a particularly American trauma, the film's topical riff on its subject (plus its advantage in being one of the first of a crop of movies inspired by the Iraqi conflict) will ensure solid overseas business.

Hank is a former military MP who has now retired and moved back to the Tennessee home he shares with his wife Joan (Susan Sarandon, who makes the most of her limited screen time as the bereaved mother of not one but two soldier sons - another died years before in a helicopter crash).

When his surviving son Mike is reported as having gone AWOL from his base in New Mexico, Hank (who wasn't even aware Mike was back from Iraq) drives across to Albuquerque to look for him.

It soon transpires that Mike has been savagely murdered. Bottling up his grief, the stiff, formal ex-sergeant, who is lost and bewildered in this strange new world of strip-joints, mobile phone videos (like those shot in Iraq by his son) and drug-taking recruits, pesters junior detective Emily Sanders (Charlize Theron) to take on the case and nail the culprits.

Of course there's mutual distrust, and of course it slowly thaws. Hank is not used to working with women, and he's impatient with Emily's lack of investigative technique and discipline, while Emily, while ready to learn, resents the old man's quietly arrogant conviction that he knows best.

Theron is always watchable, but her character is more conventionally written than Jones': the conflict with her sexist, patronising male colleagues is predictable, and there should be a Hollywood moratorium on the cliche of the feisty single mom with a mop- headed son who is wise beyond his years.

Visually, Haggis takes a step backwards from the more expressionistic Crash, though one assumes this is deliberate: DoP Roger Deakins' emphasises the scrappy casualness of this slice of Americana, and some of his framings (especially of interiors) seem almost careless.

Mark Isham's orchestral score pushes the sentiment button, and a final song by Annie Lennox feels at first like a corny descent into slush - until the film's striking final frame provides a reality check, and suggests that Haggis has been lulling his viewers in order to make the closing upper-cut all the more effective.

Director

Paul Haggis

Production companies

Summit Entertainment and

Samuels Media present

in association with

Warner Independent Pictures

and Nala Films

a Blackfriars Bridge production

International sales

Smmit Entertainment

Producers

Laurence Becsey

Patrick Wachsberger

Steven Samuels

Darlene Caamano Loquet

Executive producers

Emilio Diez

Barrosco

Bob Hayward

David Garrett

Erik Feig

James Holt

Stan Wlodkowski

Screenplay

Paul Haggis

based on an article by Mark Boal

Cinematography

Roger Deakins

Production design

Laurence Bennett

Editor

Jo Francis

Music

Mark Isham

Main cast

Tommy Lee Jones

Charlize

Theron

Susan Sarandon

James Franco

Jonathan Tucker

Jason Patric

Josh

Brolin

Jake McLaughlin