It's a fine old down-at-heel Irish week in the London theatre with the great revival of Martin McDonagh's The Cripple of Inishmaan now followed by a superb, vivid and violent new play by Conor McPherson. The island peasant no-hopers of eighty years ago are ushered out the door by the inner city dead beats of today.

Ciarán Hinds in The Night Alive
Ciarán Hinds in The Night Alive
McPherson directs his own production, which is set by the suddenly ubiquitous Soutra Gilmour in a large, shabby Edwardian house near Phoenix Park in Dublin. The house belongs to Maurice (Jim Norton) but this big messy room we are in is the "flat" of his nephew Tommy (Ciarán Hinds), an odd job man with stained T-shirts and lank hair who chews dog biscuits and grooves along with Marvin Gaye.

Tommy is giving shelter to a bloody, beaten-up girl called Aimee (Caoilfhionn Dunne) and fending off the demands for petty cash from his "freelance associate" with a borderline disability – ie, slow-witted sidekick – Doc (Michael McElhatton).

McPherson positively roisters in the language of this situation, ratchets up the tension; I've rarely seen such a brilliantly fused improvisation on Harold Pinter and David Mamet at once. Doc won't be fobbed off with cigars or banana sandwiches for payment; the riff Tommy gets out of his stale cigar dealing is a good example of how McPherson can spin rhythmic linguistic comedy all night long.

And there's one gorgeous moment when the three of them – Tommy, Doc and Aimee – are briefly transfigured in a weirdly co-ordinated dance routine, as if the secret of getting along together is not in fact talking at all after all.

Tommy is separated from his wife and daughters and drawn towards the waif-like, washed-up refugee, who may be a prostitute; meanwhile, her boyfriend, Kenneth (Brian Gleeson), is hunting her down in his vomit-stained burgundy suit and first surprises Doc with a vampiric attack ending in a vicious hammer blow and punch-up inside the toilet.

Hinds, who recently played opposite Scarlett Johannson in Cat on a Hot Tin Roof on Broadway, has been away from our stage for so long that this seems like a fresh start for him, and it's certainly a new kind of role. The leather-clad Achilles at the RSC has become a seedy old middle-aged has-been of the downtown pound stores and chippies.

But as always with McPherson, there's a glow and a poetry about these derelicts, the younger ones supervised in the critical, nostalgic bollox of Norton's bass-voiced Maurice, who has one magnificent drunk scene followed by a stately entrance in barathea blazer and club tie. Pinter himself might have played this role one day.

Absurdity and sorrow mark these people of the dregs; and in Caoilfhionn Dunne, shining like a pale star in a hag black sky, I reckon we've seen the best new actress of the year, and certainly the one most difficult to second guess, let alone spell.