It may be hard luck on DC Moore that his Afghanistan play The Empire seems part of an almost exhausted genre after similar scenarios by Roy Williams and Simon Stephens, not to mention the Tricycle epic of short pieces by David Edgar, David Greig and the rest.

But there is a hypnotic, elliptical quality to Mike Bradwell’s outstanding Upstairs production which dumps us inside an abandoned compound – designer Bob Bailey’s walls are blasted with holes, the ceiling open to the sky, the floor caked in rubble – and leaves us to sweat it out with the soldiers.

So intense is the heat, so powerful the sense of being part of a dangerous lull in the action in this part of the Helmand Province, that the audience sustained a casualty at the performance I attended, a middle-aged lady staggering to the end of a row and out to the stairs for revivifying treatment.

After a skirmish which has left one British soldier with his face blown off outside, lance corporal Gary (Joe Armstrong, uncannily resembling a taller version of his own father, the great Alun) and his taciturn Afghan sidekick, Hafizullah (Josef Altin), also known as “Paddy,” drag in a body bag with a Taliban prisoner Zia (Nav Sidhu).

Another Afghan soldier (Imran Khan) calls by unhelpfully to urinate on the captive, who has come round and claimed to be a Brit himself from Newham who was kidnapped by the Taliban on a business expedition with his uncle from Lahore in Pakistan. The commanding officer Simon (Rufus Wright, a dead ringer for Prince William) is awaiting the arrival of a Chinook to clear the area.

Our so-called war on terror is turned inside out as a reversible cloak disguising a can of class and racist worms that have wriggled away for generations. Gary jumps sadistically on Zia’s leg. Simon confirms his “posh” status. Zia spills a torrent of abuse in all directions: how could he not be angry living with you people? What is so great about imposing our version of law and order when democracy sets such a bad example?

Piggy-in-the-middle Hafizullah keeps mum. This slice of life realism ends up leaving some awkward questions unanswered and, with a down-beat non-flourish, the action expires in a cloud of dust and helicopter noise.