TOM Murphy's theatrical derivation from Oliver Goldsmith's The Vicar of Wakefield was not best served last night by Patrick Mason's direction. Elegantly, expensively, yet sparsely (in terms of place and atmosphere) set by Francis O'Connor, it seemed determined on its course as a kind of medieval morality play for the whole of its long first act. The pace was slowly measured and the tone unvarying. Lines more risible than funny went by with the uneasiness of some titters and much silence. The Rev Dr Primrose, wrenched from his living in Wakefield by his misplaced trust in people to whom he entrusted his modest fortune, seemed set on his Job like course to bring down not only himself but his entire family by his absolute faith in his God's verities and his own goodness. The longer it went on, the more firmly were he, his more venal wife and the kids ensconced in the whale's potentially lethal belly. This seemed like serious stuff.

And then, scarcely 20 minutes before the end of the second act, with the vicar in jail for debt, his son charged with murder, his daughter allegedly dead, his wife in despair and the mysterious Mr Burchill intervening, it turned out that this was not medieval morality after all: it was Victorian melodrama played ford laughs. Had there been some more obviously comedic signals in staging and performance at the start, the ending - might have provided triumphant comedy rather than mere relief from a moral tract. The makings of a good moral comedy were there in the text from the start, but were not allowed to make themselves theatrically evident.

Jim Norton's Dr Primrose: impeccably and consistently portrayed, emotionally rounded and intelligently interpreted. His was never the task to be funny. Deirdre Donnelly's Mrs Primrose, set on finding the best financial marital placements for her daughters and the best opportunities for husband and sons, is suitably strident, but could have been allowed to be more comedic. David Herlihy's Mr Burchill is perfectly enigmatic, never revealing whether he might be a good or a bad angel until that last 20 minutes. Frank McCusker's rapacious Mr Thornhill is admirably and disgustingly wicked throughout, and John Olahan as his side kick remains nicely ambivalent. The rest, for want of richer sharper words and clearer directorial intention, can do no more than be ciphers.