To be trapped in school forever, doomed to endless repetition, is a familiar nightmare. In Pat McCabe's adaptation of his novel, The Dead School, an entire lifetime is reenacted in a national school classroom, as the headmaster, Raphael Bell (Mick Lally), replays his favourite memories for a captive audience of pupils.

In this Galway Arts Festival/Macnas co-product ion, the novel has been both compressed and prised open: a taunting chorus of pupils plays every character in Bell's life story, while the creative use of masks adds a richly-expressionist dimension. Bell's formative years, his appointment as headmaster and his courtship of his wife are presented against the backdrop of a heroic nationalist narrative, whose touchstones are the Irish language, Count John McCormack and the Eucharistic Congress of 1932. His classroom and vocation constitute his whole world, until it collides with another planet: post1960s Ireland, represented by the young dope-smoking teacher, Malachy Dudgeon (Aid an Kelly).

There are some wonderful moments: the birth of Raphael from his mother's legs as a grown man; the masked heads of the pupils' "mammies" which emerge from blackboards at the sides of Tom Conroy's slanting, elongated set and chant their disapproval; the disembodied head of the Cigire, who floats in as an illuminated man-in-the-moon; the pupils' gleeful destruction of the classroom as the action moves into a farther recess of Bell's rapidly disintegrating mind.

But, while Joe O'Byrne's production works extremely well at a conceptual level, some essential chemistry is missing: the performances have not quite gelled and the chorus maintains a note of shrill, comic exaggeration that has no real levity and threatens to become laboured; certain key moments, such as the murder of Raphael's father by the Black and Tans, lack emphasis and clarity; and, most crucially, the final encounter between Dudgeon and Bell lacks the emotional impact it demands, despite the depth and range of Mick Lally's portrayal of Bell's deterioration. When this play's desperate comedy is more effectively communicated, its imaginative vision will be memorably matched.

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