Edmond, National Theatre, Olivier, London

Branagh acts mad, bad and racist

After an absence of eleven years, Kenneth Branagh makes an impressive return to the London stage - and a belated debut at the National Theatre - in Edward Hall's balefully witty revival of Edmond, a strange and provocative moral fable by David Mamet, first produced in 1982. It's a short piece, but it plunges into frightening emotional extremities and it's not hard to see why the title role has tempted Branagh back. He plays a middle-class Manhattan businessman who is assured by a fortune-teller that he is a special person living in the wrong milieu. Accordingly, he leaves his wife and, in an effort to find himself, descends into the nightmare of New York's sleazy underbelly, populated by cheating pimps, whores and three-card trick players.

Starting as a comically conventional and naïve figure who has to have a calming fag before he can drop his underpants in a hapless encounter with a prostitute, Branagh's excellent Edmond turns into a seething animal after the experience of being mugged and robbed, and subsequently insulted by an unhelpful hotel desk clerk. Alarmingly close to the surface of this repressed, respectable person, Mamet indicates, there is a raging racist, homophobe and misogynist. But Branagh continues to exude a residual, sympathetic ordinariness in the episodes that propel the protagonist into hellishly extraordinary situations. This tragicomic incongruity is valuable because it emphasises the everyman quality in Edmond and instils a the feeling in the audience that there, but for the grace of god, go we.

Each nocturnal misadventure rips away another layer of surface civilisation. A bigotry he scarcely knew he nursed cascades from him in a poisonous torrent in the scene when he batters, and hurls hair-raising racist abuse at, a violent black pimp. Absurdly pumped up with his deluded new sense of authenticity, a half-naked Branagh is very funny as he preaches his gung-ho philosophy of instinctual living ("There is no law... there is no history... there is just now") to Glenna (Nicola Walker), the acting-student with whom he has just slept. When she refuses to play his game and testify to the fact that she is essentially just a waitress, he slashes her to death with his recently purchased survival knife.

With a star like Branagh, who can pull in the crowds, the Olivier must have seemed the obvious venue. But though the various locations for this episodic and staccato piece swirl in fluently on the revolve, there are times when the production strains to fill the epic space. Joseph Mydell's preacher and his neon cross are suspended so high above the stage that the visual effect is more of a portentous heavenly visitation than a common-or-garden New York mission and, in the sequence where Edmond is identified and apprehended, the underpowered activity in the aisles merely emphasises how ill-fitted such scenes are to the Olivier's monumental scale. An in-your-face production in the Cottesloe might have suited the material better.

I also have doubts about the weird suggestions of redemption with which the proceedings conclude. The preoccupation with race that runs throughout the play comes to a head when the now imprisoned Edmond is raped by his hefty black cell mate (Nonso Anozie), and undergoes a breakdown that dismantles his sexual and social identity, paradoxically freeing him by giving him the chance to start again from absolutely nothing. The play ends with the two of them exchanging a goodnight kiss. But this touching embrace (greeted by laughter on opening night) illustrates, with an almost parodic neatness, Edmond's hard-won wisdom that "every fear hides a wish". In the circumstances, you feel uncomfortable that the black character has no other function than to be the ironic agent in the rehabilitation of a once-racist white hero. As an individual seen in his own right, the cell mate is a huge improvement on the pimp who taught Edmond that black folk are "people, too" by dint of being battered by him. It's hard to concur with Mamet's contention that Edmond is a "very, very hopeful play".

To 4 Oct (020-7452 3000)