Edmond, Olivier Theatre, London

Branagh makes an emotional return to the London stage in provocative moral tale

After an absence of 11 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 extremes, 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 nervous and conventional figure who has to have a calming fag before he can drop his underpants in a botched encounter with a prostitute, Branagh's Edmond turns into a seething animal after the experience of being mugged, robbed and insulted by an unhelpful hotel desk clerk. Alarmingly close to the surface of this respectable person, Mamet indicates, there is a raging racist, homophobe and misogynist.

That bigotry cascades from him in poisonous torrent in the scene where he batters and hurls abuse at a black pimp. Ridiculously pumped-up and preening with his deluded new sense of authenticity, a half-naked Branagh is very funny as he preaches his gung-ho philosophy of instinctual living to the acting student (Nicola Walker) with whom he has just slept.

When she refuses to play his game and testify in revivalist fashion to the fact that she is 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 with lofty neon crosses and under-powered activity in the aisles.

In-your-face promenade production in the Cottesloe might suit the material better. I also have doubts about the weird suggestions of redemption with which the proceedings close. Raped by his hefty black cellmate, Edmond seems to undergo a breakdown that dismantles his sexual and social identity and paradoxically frees 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 illustrates, with an almost parodic neatness, the notion that "every fear hides a wish'' and it reduces the black character to being simply the agent in the rehabilitation of a once racist white hero. As an individual seen in his own right, he is not much of an improvement on the black pimp Edmond battered. One might wish to question Mamet's contention that this play is "very, very hopeful".