Stoning Mary, Royal Court, London

At the beginning of Stoning Mary, the words "The Aids genocide" are projected on to the floor of the Royal Court, wafting gently across it to settle on the back wall. Ah, I thought - nothing like knowing where you stand on an issue.

At the beginning of Stoning Mary, the words "The Aids genocide" are projected on to the floor of the Royal Court, wafting gently across it to settle on the back wall. Ah, I thought - nothing like knowing where you stand on an issue.

As it turns out, knowing where you stand is far from easy in Debbie Tucker Green's play. The action, which takes place in a sky-blue arena, with little heaps of stones washed up around its edges, is composed of three interlocking stories.

In "The Prescription", a husband and wife argue over which should receive life-saving drugs, given that they have enough money for only one; each pleads, accuses, promises to care for the other and their daughters. "The Child Soldier" features a middle-aged man and woman squabbling over the memory of their son, each claiming the lion's share of his affection.

The last segment is "Stoning Mary". A young woman - Mary, the only named character - is visited by her sister in prison, as she waits to be stoned to death; they too slide into bickering and mutual contempt. The stories are united by the figure of a young boy, shaven-headed, armed with a machete, who bursts in on the husband and wife of "The Prescription". He, it seems, is the lost boy of "The Child Soldier"; Mary is one of the daughters referred to in "The Prescription": her crime was to murder the boy, in revenge for the killing of her parents.

The dialogue is elliptical, non-specific, built on repetitions and variations of words and phrases. The delivery is quick fire; actors frequently speaking over one another. Some characters are accompanied by "egos" - second-selves offering a kind of commentary on motives and suspicions: the virtuosity with which they place their lines in the gaps between words is highly impressive.

Despite the obscurities of the script, the implied storyline is clear enough. What is clarified by the projected titles is the context. Though the cast are all white, and speak with south-east English, working-class accents, their situations allude to crises that are specifically African. Presumably, the point is to strip the human agonies of any cushioning of race and geography. Once the connection is made, though, this device feels clunky. And by clumping together these different situations, Tucker Green seems to imply a generic Africa; a dark continent.

Though Stoning Mary is only an hour long, it doesn't manage to sustain its emotional effects: intriguing, but not quite successful.