World Music, Donmar Warehouse London

The MEP Geoff Fallon is a very mixed-up guy - appropriately, as World Music is a mixed-up play. The main character of Steve Waters' drama is supposed to be our guide to the complexities and treacheries of recent African history. Never off stage, either as the present-day middle-aged man or the youth teaching children in Irundi (an amalgam of Rwanda and Burundi) 20 years ago, Geoff both shows us the facts about Africa and misinterprets them. But, either as participant in the action or its explainer, he is actually an obstacle to our involvement in the play.

Conceived as a bluff, hearty, no-nonsense type, Geoff is, in fact, noisily dull. When he's not declaring his impatience with bureaucracy ("Let's open some doors, then. Let's open a load of windows"), he's telling a cleaner (Nikki Amuka-Bird), for whom English is a third language, that a document is about "infrastructural convergence in the Baltic states". Kevin McNally accentuates the character's incessant demonstrations of his rough good-heartedness by sternly pointing his finger, pounding a fist into his palm, and throwing papers around. (His colleagues, in Josie Rourke's production, are also prone to strange gestures: one stands with her arms folded across her chest and rocks from side to side, another extends his hand, in greeting, palm down, as if he expects it to be kissed.) With his lack of social and political savoir-faire, his talk of "nuance" and "ambivalence" and "catharsis," Geoff seems more academic than MP.

Yet as World Music continues, one is drawn into its subjects - the exploitation/ patronisation/misunderstanding of Africa by Europe, and the African conflict between tribe and nation. Is what we might today call "pre-emptive justice" vengeance under another name, or simply survival insurance? We are introduced to the developing nation, split between the once-dominant Kanga and their new masters, the Muntu, through the young Geoff (Paul Ready, endearingly awkward), who lives with the village's head man and is drawn to his servant, Odette. In the present, Geoff - less believable as the young man grown older - takes Amuka-Bird's character back to his flat. Since he is not interested in sex, this is an odd move, but Waters needs her there - an Irundi, she fills Geoff in on a neglected aspect of the tribal massacres. This provides the play's one moment of heartfelt emotion, and Amuka-Bird seizes it in an extraordinary aria of self-immolation.

The greatest conflict in World Music, however, is between its topic and what is done with it. A lot of information is thrown around, but we are left uninvolved. In part, this is down to Waters' concern with making Geoff sympathetic, in part to the clumsy dialogue and the confusing shifts from the present to the past. What is not in dispute is the delicacy and grace of Amuka-Bird and of Assly Zandry, as Odette. Two players don't make an orchestra, but these actresses make some beautiful music.

To 13 March (0870 060 6624)