Untouchable, Bush Theatre, London

Superb pair of Northern soul sisters

It took me a little while to work out what the girls in Untouchable, Simon Burt's new play, were talking about. They kept referring to "doing wakey". The mind raced with a range of possibilities, from delivering early-morning calls to organising post-funeral festivities. What they mean, it gradually becomes clear, is painting Wakefield red – to "do Wakey" and its nightlife "until it can't stand no fucking more".

That's the ambition of the two 18-year-olds, best friends from way back, who install themselves in a cramped little flat with one single bed in the clubbing part of the city. The lippy, live-in-the-moment Lou (a superb Samantha Robinson) has ditched her college course in hotel services; it cut too much into her bartending shifts and she needs the tips to pay for the slinky clubbing dresses she wears when she goes on the pull. She is currently majoring in hedonism because she can't figure out what else she wants from life.

The much less reckless and experienced Manni (Pooja Shah), on the other hand, is "little Miss A-levels". She's still studying for university entrance and four months into a frustratingly sexless relationship with Mehir, who – not yet 20 but feeling that it's time to settle down – would seem to be pretty much at the opposite end of the scale from Lou and her rhetorical question: "Don't you ever just want to have someone so like now? Now in the club bog like?"

So the flat is like an escape from prison for both of the girls. They can wear what they like, stay out as late as they like and bring back who (or what) they like. Or they can merely sit and talk. On their inaugural session, Lou raises a bottle of vodka to this vista of unqualified liberty: "Tonight, it's just me and thee an' we keep going 'til we watch the sun rise over Argos superstore."

The demise of that dream is charted in a series of groggy post-clubbing scenes that are beautifully handled, in all their rueful, yet resilient comedy and sad, floundering squalor, by Natasha Betteridge's warm, sympathetic production. There are no devastating surprises in what happens. Only on one occasion are the tight sleeping arrangements an embarrassment – when Lou, unaware that Manni is dossing on the floor, has sex and then opens up her heart to a guy who turns out to be singularly unworthy of that honour. Manni learns the hard way that to the repressive Mehir, who tries to dissuade her from going to university, she simply represents the perfect form of his parent's wishes.She is torn between distress at her friend's decline into vodka-soaked fecklessness and anxiety about being left behind when, in one way or another, the intellectually smarter Manni inevitably moves on.

It's the gutsy, colloquial vigour of the dialogue and the shrewd insight into female friendship that make Burt's debut piece such an attractive proposition. The girls have a relationship where the various inequalities are doomed to loom larger, but Burt captures the last period when Lou's fiercely protective pride in Manni can be balanced by the latter's idolising of her friend's precocious sexual savvy. Having proved that "doing Wakey" is not all it's cracked up to be, they promise each other that, one night before Manni goes to university, they will "do Leeds". You are left with the wistful feeling that this appointment may well not be kept. It's a tribute to the psychological inwardness of the play that you can scarcely believe it was written by a man.

To 21 Dec (020-7610 4224)