Theatre: In a Little World of Our Own Peacock Theatre, Dublin

If working-class Ulster Protestant culture lacks a contemporary voice in the arts, it is fast developing one in 32-year-old playwright Gary Mitchell, whose work is often set in his native, sprawling Rathcoole in north Belfast. The first Northern Irish winner of the Belfast-based Stewart Parker Award in 1994, Mitchell developed his writing muscles over a dozen radio plays with BBC Northern Ireland; and although the Belfast Lyric turned down his latest play, In a Little World of Our Own, last week it received a fine premiere in Dublin's Peacock (the smaller, sister stage of the Abbey) from five of the North's best younger established actors, led by Armagh-born director Conall Morrison.

Set against the on-going tremors of conflict - with all the frisson of immediacy this entails - In a Little World of Our Own is a wry, tense, moral and psychological whodunit, contained within the sundering household of a UDA hard man, his mildly retarded younger brother, and another brother about to jump ship into God-fearing marriage. Major events take place off-stage: a mother lies dying upstairs; a girl is raped and murdered; and the victim's father, a former paramilitary turned politico, goes gunning for vengeance. No one believes it was the "Taig" (Catholic) last seen with her; so was it the simpleton, as everyone suspects, or worse, the unreconstructed hard man, whom everyone treats with respect as much as fear?

Sporting a pencil-thin Vandyke, Stuart Graham is the coldly menacing Ray, dominating his child-minded brother Richard (Marc O'Shea), the weak, puff-pastry brother Gordon (Sean Kearns), and the latter's prim, evangelistic fiancee, Deborah (the weakest character, made real by a layered performance from Andrea Irvine). Ray even terrorises Walter (an icily timed Lalor Roddy), the oily, anorak-clad go-between who emerges as power-broker and grim arbiter, once things really start "getting out of hand".

The script is tightly contained, unveiling the machismo loyalties and axiomatic sectarianism in a society distrustful of police. In fact, it's a wee bit reminiscent of some of Graham Reid's terser, early plays, and apart from the very young vernacular, it's hard to see it (as many recent North of Ireland plays have been characterised) as a "ceasefire play". All mentions of a ceasefire have been excluded, and with guns floating around and characters trying to better themselves against the odds, this has the curious effect of emphasising the interminable siege-status of a sealed culture - whatever the official line of the loyalist organisations.

But it would be a mistake to read too much into its allegorical workings - it's more a piece of accomplished realism wound into a taut thriller. From the word go, you have to concentrate hard on the rapid-fire dialogue and scene-setting, but that's the director's style: heavy top-spin on pacing, punching home the everyday humour, and throwing awkward silences into telling relief. And it works again, making for a gripping and memorable piece: the insane order of the living-room floating within the cracked, pebble-dashed surrounds of Kathy Strachan's bleakly naturalistic set.

To 15 March. Booking: (00 35 31) 878 7222