THEATRE / Acts of rough magic: Paul Taylor reviews The Mountain Giants, Pirandello's final, unfinished play at the National's Cottesloe

THIS PLACE would make Prospero's island look more than a touch niggardly in the tricks and special-effects department. 'Would you be so kind . . . ?' asks the self-satisfied old sly-boots of a magician (Desmond Barrit), nonchalantly creating a lovely pink sunset over the villa's broken glass roof. Feats of this kind (conjuring fireflies from the dark, say, with a snap of the fingers) are among the least of his accomplishments, though. With Cotrone and his spirits around, you should keep a close watch over your dreams or you might find they are being simultaneously enacted in public. Charm the birds from the trees? This magician is more likely to charm the guilty secrets from your soul.

Keeping illusion and reality, or art and life, crisply distinct is not a top priority with Cotrone. He presides over a world where puppets can jerk to life and waltz with a visiting troupe of actors, where you can look at your own sleeping form, and where gold- faced angels think nothing of entering through brick walls. No wonder some of the itinerant thesps here feel, punningly, a shadow of their former selves. But where the hell are we? In a play by Pirandello - where did you think?

His final, unfinished play, to be exact - one which in this fascinating British professional premiere (directed by Willian Gaskill in the Cottesloe) comes with a last act provided by Charles Wood. It is a tantalising, paradoxical meditation on the role of art in society, its very incompleteness perhaps a testimony to Pirandello's ambivalence on the subject.

Set in the magician's fantastical villa where he resides, a bloated epicure of illusion, with his grotesques and zanies, the drama is triggered by the arrival of a troupe of worn-down, bickering luvvies. They have been touring in the posthumous play of a poet who killed himself for love of a leading actress, the Countess Ilse (adroitly performed by Sian Thomas).

If the magician's removed and morally unaccountable wizardry represents an extreme notion of 'pure theatre', then the Countess (whose sense of mission is far from untainted by actressy self- regard) stands for an art that would like to dedicate itself to the public good but, being essentially art-for-art's-sake, hasn't the faintest idea what the public wants or needs.

This becomes brutally clear in the last act, where the thesps, about to do their play, are seen 'separated only by a rag of curtain' from a jeering audience composed of the philistine folk who slave uncomprehendingly for the local master race of mountain giants. When Ilse goes out to brave them, it's like a lamb strolling into an abattoir. Unable to understand each other, the slaves of art are destroyed by the slaves of power- worship.

Where Pirandello's portion of the play is firmly located in a world of myth, Wood allows actual history to permeate his version of the ending. Reminding us that this dramatist had made the mistake of looking to Fascism as a philosophical remedy, there are pointed references to Hitler and Il Duce, a visit from an officious censor, and we learn that the actors' play has been banned in Berlin.

This glimpse of the real world feels revealingly and perhaps damagingly odd. For though the magician finally tells the actors 'You exclude yourself from life at your peril', there is in the play hardly a robust sense of ordinary existence for the illusions and artiness to brace themselves against. But Gaskill's intriguing, well-acted production brings these latter to beguiling life.

In rep: Cottesloe, National Theatre, London SE1 (071-928 2252)