Inherit the Wind, Old Vic, London

A coruscating courtroom battle

After the ill-fated musical version of Gone with the Wind, you might have thought that Trevor Nunn would have wanted to steer clear of the American South.

But the director is back there now in the Old Vic's remarkably involving revival of Inherit the Wind. This 50s play by Jerome Lawrence and Robert E Lee is based on the famous 1925 "Monkey Trial" in which a young Tennessee teacher, John Scopes, was arraigned for flouting state law by instructing children in the ideas of Charles Darwin. It may be a clunky old war horse, but the play is well worth re-mounting. Given that an alleged 46 per cent of Americans believe that Darwin was mistaken and given the muscle of the creationist lobby, its defence of the right to think for oneself is as timely as ever. It also offers the delight of watching two fine actors going head-to-head in the climactic courtroom ding-dong.

Kevin Spacey plays the smart-as-hell Chicagoan, Henry Drummond (a barely disguised version of Clarence Darrow) the libertarian lawyer who volunteers his services to the defence because he believes that not just Scopes but civilisation itself is on trial. Opposing is David Troughton's Matthew Harrison Brady (a dead-ringer for William Jennings Bryan) a demagogue whose only idea of a good read is the Good Book which he takes absolutely literally.

Spacey's superb Drummond is a wily, almost negligently charismatic legal titan who ambles across the courtroom on splayed, arthritic legs while running rings, intellectually, around his adversary. Matching him in stage presence, Troughton portrays Brady as, in part, a mountainous overgrown child, greedy for public approval and willing to resort to the cheapest rhetorical tricks to get it. By shameless mispronunciation, for example, he repeatedly puts the "evil" into "evolution". But, boom and bellow as he might, Brady fails to disguise the fact that these are the blustering noises of a desperate dodo – as is painfully demonstrated by Drummond's table-turning coup.

Denied the right to summon expert witnesses of his own, the defence lawyer decides to call Brady himself to the stand. While cross-examining him on his bible expertise, he exposes the ludicrous incoherence of this fundamentalist's beliefs. Spacey's comic timing is richly evident here. Informed that Brady thinks the world was created on 23 October 4004 BC at 9am, Spacey lavishes seconds of silent consideration on the notion, before casually flicking this lethal pellet of a question: "Would that be Eastern Standard Time?"

Though you occasionally feel that Nunn wouldn't be averse to turning this into a full-scale musical, he does a spirited job in creating a sense of the local community. Scenes are connected by a hymn-singing, banner-waving crowd of God-fearing worthies. The prejudice the defence was up against is communicated in the escalating zealotry of prayer-meetings held on the eve of the trial. Here, Troughton movingly signals the demagogue's underlying humanity when he gently restrains Ken Bones' hell-fire preacher from denouncing his own daughter for the sin of being Scope's troubled girlfriend.

Mark Dexter makes a strong impression as a suavely sceptical visiting reporter. By the end, this cynic has parted sympathies with Drummond who winds up, in a rather rushed development, arguing that the Bradys of this world have the right to be wrong with impunity. Was that a sentimental sop to the Broadway of the Fifties? Or in the rebuke it offers to the mounting intolerance of fundamentalist atheism, is it another way in which Inherit the Wind continues to put the present on trial?

To 20 December (0844 871 7628)