Fix Up, Cottesloe, National Theatre, London

Kwame Kwei-Armah rightly bagged a most-promising playwright award for Elmina's Kitchen, his provocative look at three generations of black men in Hackney's murder mile.

Kwame Kwei-Armah rightly bagged a most-promising playwright award for Elmina's Kitchen, his provocative look at three generations of black men in Hackney's murder mile. He returns to the Cottesloe with Fix Up, a clearly heartfelt but somewhat creaky piece exploring the broader issue of black identity. In a conformist culture of consumerism, where people are more interested in their hair than their history, who will continue to heed Marcus Garvey's cry that "there is no future for a people that deny their past"?

"You can't replace history with hair gel," the hero indignantly protests. But the thrust of the play suggests that this process is all too possible. Brother Kiyi, a black intellectual originally named Peter Allan, runs a bookshop in Tottenham whose shelves groan with high-minded tomes about black heritage that precious few people actually buy. Spending his days listening to tapes of Garvey and James Baldwin, this figure with his great mane of greying Rasta dreadlocks is more dreamer than businessman. The premises are in danger of being converted into luxury flats and - amusingly, given his own defiant coiffure - a store flogging Afro Sheen and other black hair products.

One of the strengths of the play is that it does not present Brother Kiyi (powerfully played by Jeffery Kissoon) as a simple case of beleaguered, pure idealism. His generosity is evident from the paternal care he takes of Carl (Mo Sesay, delightful), an illiterate former crack addict, and from the way he is prepared to spread enlightenment by lending out books for free. But there is also something remote and emotionally withholding in him, as witness the hurtfully rationed intimacy of his relationship with Claire Benedict's sympathetic, humorously deadpan Norma, the friend prepared to give him her savings in an effort to rescue the situation. He's touchy and arrogant, and the suspicion arises that history, for him, is as much a psychological refuge as the pointer to a better future.

The irony whereby this scholar of slave histories turns out to have suppressed the darkest facts of his own past is conveyed via a plot whose tactic of delaying the obvious revelation can't help but feel old-fashioned and melodramatic, even in Angus Jackson's absorbing and well-acted production. Nina Sosanya's Alice, the sexy feminist newcomer of mixed race (or "dual heritage", as she prefers to call it) loiters in the shop with (for the audience) an all-too-overt narrative and thematic intent. She comes across more as a catalyst than as a character that has been imagined from within.

She is there to spark nostalgia for his old, lost anger in Kiyi and to provoke an eroticised hostility in Kwesi (Steve Toussaint), the handsome, leather-coated militant who lives in the flat upstairs. His dogmatic separatism causes him to scorn and distrust dual-heritage people such as Alice, almost as though they were themselves blameworthy examples of what overexposure to white folk can produce. It also, in a plot twist that is genuinely thought-provoking, involves him in a crucial act of betrayal. Where will the revolution start - in a bookshop full of volumes nobody wants, or in the expanding properties bought with the profits from the sale of Afro Sheen?

In rep to 23 March (020-7452 3000)