For the production that marks, respectively, their return to and departure from the Royal Shakespeare Company, neither Ralph Fiennes nor former artistic director Adrian Noble have taken the easy option. Henrik Ibsen's Brand is a morally rigid, often loathsome, Lutheran preacher trapped in a long and difficult play - a challenge both to act and to stage.

In fact, Ibsen himself never intended Brand to be staged. Written as a "dramatic poem" in 1865, it didn't receive its premiere until 1885, when the unwieldy text required a whopping six and a half hours of performance time.

Noble's production of Michael Meyer's existing translation clocks in at just under three hours (including interval) yet still fails to excise vast tracts of sermonising, particularly in the overly long first half during which Brand, the missionary preacher, returns to the frozen Norwegian north of his unloved loner childhood to be hailed as a reluctant local leader. By comparison, the second half - when his own brand of uncompromising "all or nothing" religion takes its full, devastating toll - seems perfectly formed, a tragedy in two acts.

Fiennes' portrayal is a highly detailed one. As a friend commented to me afterwards, there's no doubt we're in the presence of great acting here. Fiennes' Brand stoops like an old man from the weight of his calling, his movements stiff and mannered as if the whole of his wiry body is one ruthlessly clenched muscle. He pinches his lips into a permanent frown and speaks with obvious effort, as if his words are chewing up the insides of his mouth before he has a chance to spit them out with distaste. It's sometimes difficult to understand how such a pitiless prig can inspire such a passionate following, but you don't want to take your eyes off him nevertheless.

For her part as his chief disciple-turned-wife Claire Price is stunning, delivering a highly emotional study in sacrifice and loss. Elsewhere, there is able support from Oliver Cotton as the conscienceless mayor, Susan Engel as Brand's unrepentantly greedy mother and Alan David as both the lax doctor and corrupt provost.

Peter McKintosh's minimalist set - framed by a semi-circular wall of grey slats that occasionally part, chasm-like - finds the company conjuring up from thin air the grim realities of their icy mountain region. It would have been interesting to see the production in Stratford's intimate Swan, where it was first staged, but you don't feel cheated having it re-set in the proscenium arch Haymarket.

Theologically dense and dramatically difficult, this Brand may not make for a comfortable evening, but by the end, the audience reaps ample benefit for its perseverance.

- Terri Paddock