The good news is Josh Hartnett can act. The bad news? This adaptation of Rain Man might be a shrewd business move, but it is a cynical artistic one. Whilst the nostalgia connected to the film and the hysteria connected Hartnett might pull in the punters, Rain Man is a prettily packaged but empty production.

This is largely down to logistical problems, with writer Dan Gordon squeezing this classic film into a relatively short two hour production. Not nearly enough time is spent developing the central relationship between the two brothers, and despite a consummate performance from Adam Godley as the autistic Raymond, the sentimental ending leaves one cold.

The peculiarities of putting a movie star on stage are obvious as soon as the curtain goes up and an audience packed with teenage girls begin to scream. This then is going to be a hugely biased experience – one in which a rapt audience are willing Josh Hartnett to succeed. Despite a shaky and rather wooden start, Hartnett settles down into a solid if not particularly nuanced performance. His is a straightforward role to play – the heartless businessman turned sympathetic brother – and Hartnett is never forced outside his comfort zone. Godley has a far more daunting task and the commitment and detail contained in his performance is impressive. It is his role that lends this production substance and without it, this wafer-thin adaptation would have crashed and burned.

Despite Godley’s best efforts, his performance is undercut by a fairly loose and manipulative script. Though the credibility of Godley’s interpretation is never in doubt, the severity of his characters’ autism fluctuates between scenes. Rather than committing to a faithful representation of this widely misunderstood impairment, Gordon adapts Raymond’s mental state according to the demands of each scene. So whilst it is sometimes convenient for Raymond to be removed from reality, at other times he displays a sensitivity and engagement that moments earlier seemed impossible. It is a weak artistic decision and suggests a writer and director more concerned with a slick script, rather than a more sustained and complex approach to this undeniably tricky subject matter.

It is the set that actually pulls the play together and adds a dimension that is otherwise missing. Jonathan Fensom has constructed a striking and practical set, using a series of flats to frame every scene. Instead of real spaces, each location is blocked off into a different symmetrical shape. This is reality as Raymond sees it – simple, repetitive and somehow comforting. It is a clever trick and is one of the few elements in this production that really makes us think and reassess the way those with autism see the world.

Till 20 December 2008