A Woman in Waiting, New Ambassadors, London

Thembi Mitshali curls up in a box, like a foetus. In fact, she is a foetus, impatient to be born at the King Edward Hospital for Non-European-Born in South Africa. "I am cooked! I am ready!" cries the baby, and out she pops. But, as the title says, she emerges to a world that tells her, "Wait, wait, wait." A more realistic order might have been, "Forget about it."

Living with her country grandparents while her mother works day and night in white people's city kitchens (we don't hear what her father does), Mtshali sees her parents only at Christmas, when their presents include shoes that are always too small. She counts the full moons on her fingers and two toes until they come again. Despite the pain of the material, the 50-year-old Mtshali's enactment of this part of her life is delightful, as she sheds more than four decades to become a round-eyed, impish child, sending the birds off to her mother with very important messages and scrunching up her face in anguish over the incomprehensible world of Jack and Jill.

Mtshali at last joins her mother (her father has vanished), but she is still waiting for love, or even attention, as her mother is always working, exhausted, or asleep. Soon she is working too, and soon after she is surprised to be told she is going to have her own baby ("No one had explained these things to me. No one had time"), who in turn must wait while she looks after white children. Mtshali loves the little boys she cares for, but knows that, after a certain age, they will turn into her enemy.

The show, written by Mtshali with the director Yael Farber, tells a moving story of life under apartheid, which Mtshali delivers with fluidity and force, deftly alternating prose with exuberant dances and songs, weaving the poignant moments with the comic. But it might have benefited from a more playful and symbolic production, with more imaginative transformations of the set's two boxes and a washtub.

Much more unsatisfactory are Mtshali's omissions (we never hear about the men in her life, and her children exist only as swaddled objective correlatives of sadness). Were they sacrificed to Farber's declared aim of creating a piece that would represent the suffering of all black South African women? If so, they should also have stopped before Mtshali auditioned for a local play. From this point, the beginning of her successful career as an actress and writer, the recollections sound as if they have been made many times before, and the show takes on the tone of the showbiz tribute-to-myself.

To 30 June (020-7369 1761)