The Weir (Royal Lyceum Theatre, Edinburgh)

Not much happens in The Weir. Five people enter a pub in rural County Sligo, spend the night talking to one another and then leave. But Conor McPherson's play derives its considerable power from the primal human need to tell your story and to be listened to, for the characters in the pub unburden themselves about things that lie deep within them; things dark and unsettling.

In one sense The Weir is a naturalist drama, set in the slightly shabby surroundings of Brendan's pub, evoked beautifully by Francis O'Connor's design which manages to be both minimalist and cluttered. The supernatural stories speak of a more eerie mood, but it's also too simple to call the play a ghost story. Instead, the play hovers cleverly around several different fault lines, drawing the audience in through the relationship between the drinking buddies, Brendan, Jack and Jim, together with Finbar, who isn't seen in there so often since he made it big, and Valerie, who has just moved to the area from Dublin.

It's the chemistry between the cast and their security inside the dialogue that really makes the play work. Gary Lydon holds court from his bar stool as Jack, who describes himself as a "cantankerous old bollocks", simultaneously suspicious and fond of Frank McCusker's Finbar, the flash dresser who runs the local hotel, and who they all suspect is trying to have his way with Valerie. Darragh Kelly plays Jim with the innocent good humour of Compo, while Brian Gleeson's Brendan holds slightly aloof from the company, standing behind his bar and keeping his counsel.

They are wonderful to watch as the mood darkens, however. Finbar tells the story of the time he was called to deal with a ghost in a way that seems he is even trying to convince himself, while being unable to shake off his own unease. Jack becomes more humane and more sympathetic as the talks about the love he lost, and Jim transforms into somebody who can barely believe his own story of the day he was asked to dig a grave. Best of all, however, is Lucianne McEvoy's Valerie, who gazes blankly into space while she listens to the men, but then assumes a stature and power all of her own while she tells her own story, perhaps the darkest of all.

Countless little touches add flecks of life to the texture, such as Brendan's uncertainty when Valerie asks for something as ladylike as a glass of wine, or the others' hilarity when Finbar describes a Ouija board as a "Luigi board." The ending is beautifully managed too, slightly curt as the last of them walks out of the pub to do something as mundane as giving the others a lift home, but a reminder that ordinary life carries on, despite the deep things they've been talking about. An eeriness remains at the end, though, and it's that balance of darkness shot through with comedy that makes this a good night; a celebration of storytelling and its power to transform us.

The Weir runs at the Royal Lyceum Theatre, Edinburgh until 6 February.