Unlike plays of marital meltdowns, Dance of Death proves that a fate far worse than separating may actually be staying together. In this bleakly brilliant August Strindberg classic - subtly rendered in a new version by versatile American playwright Richard Greenberg (Three Days of Rain, Take Me Out) - we bear appalled but fascinated witness to a couple bound not by love but by hate.

Three months away from their silver wedding anniversary, even in their all-consuming contempt, Edgar and Alice - the "two unhappiest people on earth" - realise that they're welded together and can't break free: "I now know that only death can prise us apart." So then, when Edgar is taken ill, the wife greets the news with positive comic relish. "He could die of this," says their visitor Kurt. "Oh, thank God!" she replies.

Marooned on a Scandinavian island known as 'Little Hell', where they've managed to alienate all and even the doctor refuses to visit, the couple stare into the abyss of their lives with a Beckettian glitter as well as gloom. There's the strangled laughter of fearing death even as it's hoped for, and the endless hours, alternately of despair and fury, to be filled in the meantime. One minute they're tenderly remembering the good times in Copenhagen and he's acknowledging: "I suppose you could be attractive.... to other people.... when it suits you"; the next, she's comparing him to manure that's "not even top grade".

These two are far from easy company, to each other, to their guest, or to us. But fortunately, the top-grade actors who take us on this long day's journey into night and the following day make it an utterly compelling one.

Ian McKellen's haughty superiority, languid self-pity and lazy torpor as the husband makes you want to strangle him. As his wife, the brilliant, brittle Frances de la Tour is a study in melancholic, withering disdain. Both McKellen and de la Tour have played these roles before, he in a 2001 Broadway revival opposite Helen Mirren; she some 20 years ago at Riverside Studios opposite Alan Bates. But you feel that, this time, they have truly met their match.

Their toxically claustrophobic dynamic is interrupted by the arrival of Owen Teale's Kurt and leads to what passes for a plot in a play that's essentially a reflection of despair. Helplessly, Kurt is trapped in the middle of the game-playing and point-scoring, like Martha and George's guests in Edward Albee's Whose Afraid of Virginia Woolf?, which was clearly inspired by Strindberg's forerunner.

A dark evening in every sense, Sean Mathias stages proceedings with atmospheric precision and intensity in the enveloping gloom of Jon Driscoll's deliberately dim lighting on Robert Jones' looming set. Frequently played by flickering candlelight, the play and its players both cast long and penetrating shadows. Though at times mordantly and morbidly funny, it's hardly an easy evening out, but it's definitely a rewarding one.

- Mark Shenton