The Bogus Woman, Theatre by the Lake, Keswick

Theatre by the Lake's newly enlarged 100-seat traverse studio offers, for those in search of darker drama to fit the mood of the Lakes, something more substantial than the plays in its main house. Here, Martin McDonagh's savagely comic The Lonesome West and Pinter's enigmatic The Caretaker frame a production of Kay Adshead's provocative and painful The Bogus Woman.

As the African poet and journalist – the "bogus woman" – who seeks asylum in England, Krissi Bohn acts to vividly realised and blistering perfection. The Bogus Woman is a monologue but, as the nameless Young Woman, Bohn gives us sharply etched encounters with some 40 characters, each with accents suggestive of class and nationality and with attitudes ranging from patronising to racist.

Having escaped from a war zone after being gang-raped and seeing her family murdered, the Young Woman might have expected to be met with compassion. Not so. From the antagonism of the security guards in the grim detention centres around which she is shunted, to the denial of basic human rights from the authorities and the inefficiency and apparent callousness of the asylum system, the odds are against her – as they are against countless other detainees.

Adshead's fluid structure allows the Young Woman to flit between the present hell she inhabits and the past hell she fled, recounting terrible atrocities, weeks spent in a claustrophobic hiding hole, and the terror of touching down, with forged papers, in a foreign and hostile environment. That's Britain, by the way.

Sophia Lovell Smith's set has to be flexible, allowing for the two other studio plays: the harsh metallic and tiled floor and ceiling (through which the Young Woman can sometimes see a strip of grey English sky) works well both as a cell and, later, a decrepit flat. Up and down Bohn paces, delivering her bleakly expressive lines in a way that is as emotionally intimate and compellingly intricate as a piece of solo chamber music.

Subtly directed by Zoe Waterman, The Bogus Woman might upset those of a delicate disposition, but it is essential watching for its cutting indictment of the way in which we, as a society, fail those who rely on us for fairness, freedom and compassion.

To 5 November (01768 774411)