American playwright Annie Baker's 2009 off-Broadway "drama class" play is set in a windowless dance studio, so the Royal Court has got its own off-piste location spot on: a cheerless community centre on the Islington, Hoxton borders, a hefty stone's throw from the new Arcola.
Baker's characters are non-metropolitan, too, five residents of a small town called Shirley, in Vermont, who have signed up for a six-week course in creative drama supervised by Imelda Staunton's no-nonsense Marty. They all have different reasons for being there.
What could have been toe-curlingly embarrassing – or downright awful – is transformed in James Macdonald's delicate and precise Theatre Local production into a group study in loneliness, neediness and confession, a sort of ambiguously theatrical A Chorus Line without the music and more of a meshing interaction across a passage of time.
And who wouldn't want to spend a couple of hours in the company of actors as clever and emotionally mesmerising as Staunton; or Toby Jones as a divorced carpenter, Schultz; or Fenella Woolgar as a displaced actress, Theresa, studying acupressure and licking her wounds; or, again, Danny Webb as James, Marty's husband, who has baggage, and an estranged daughter, from a first marriage?
"Are we going to do any real acting?" asks teenager Lauren, brilliantly played by Shannon Tarbet as a devastatingly sullen square peg with an eye on Maria in West Side Story at school and shadowy ambition of working with animals.
The dialogue takes the form of group exercises – word games, physical tableaux, confessional riffs (each character's biographical summary spoken by another member of the group) – through which real tensions and revelations prickle like little needles on a smooth skin.
And there are short sharp encounters outside the perimeter of the class, too, that deepen the new friendships, or challenge old ones. Schultz and Theresa embark tentatively on an affair, Marty finds her authority dangerously undermined, Lauren takes one dialogue game too far.
You find yourself wondering about the drama thrown back in the mirror within the circle: is it a construct, or is it a break-down, is it for real, or is it for fun? The acting leaves you in no doubt about the answers, and there's a lovely, surreal coda that speculates on the continuity of these peoples' lives and their prospects for happiness.
See also: Show Pics gallery for Circle Mirror Transformation