BOOK REVIEW / The robbers of Bruder Mouse: The unusual life of Tristan Smith: Peter Carey - Faber & Faber pounds 14.99

PETER CAREY'S fiction has always been both inventive and about invention, at once a manifestation of imaginative power and a comment upon it. From the tribute to possibility that is Oscar and Lucinda's glass cathedral to The Tax Inspector's sinister meditations visualised on Sony Trinitrons, Carey's narratives explore the reach and the limitations of the mind's power to create. As Phoebe McGrath says to Herbert Badgery, the protagonist of Illywhacker, 'You have invented yourself, Mr Badgery, and that is why I like you . . . you can be anything you want.'

In his latest, immensely ambitious, novel The Unusual Life of Tristan Smith, Carey has challenged his already broad horizons. Once again a tale about a character's struggle for self-invention, this novel takes place in the imaginary New World nations of Efica and Voorstand - conjured by Carey complete with their own lexicon and pseudo-academic footnotes on their histories and cultures. Voorstanders, to whom the novel is addressed, are inhabitants of an idealist country now mired in decadence, flooded with refugees from the lands it has conquered, and globally dominant through its cultural imperialism. Most successfully, Voorstand has exported its 'Sirkus', a flashy, laser-filled form of mass entertainment which disseminates bastardised versions of Voorstand's founding myths. These feature a range of creatures, central among them the duck, the dog and Bruder Mouse, a creepy cousin of Mickey. (Much of Voorstand, indeed, seems a dark interpretation of America's future.) Tristan Smith, an Efican, accuses: 'It was through your charm and your expertise that you conquered us, with your army, yes . . . but you kept us conquered with jokes and dancers, death and beauty, holographs, lasers, vids, with perfectly engineered and orchestrated suspense.' In sum, Eficans are enslaved by another country's national imagination.

Efica is a former colonial outpost, originally settled by the French and the English. It is a place still trying, like the novel's narrator, to define itself. Says Tristan's mother, Felicity Smith: 'No one can even tell me what an Efican national identity might be . . . All we know is what we're not.'

For Efica and for Tristan both, self-definition is a matter of the theatre. Tristan's adventures are those which literally transform him into an actor, in all senses of the word, and for the misshapen, hideous, 65lb mutant that he is, wheelchair-bound and drowning in his own phlegm, this is no mean feat. As his actress mother advises him, on pursuing his passion for the theatre: 'You must keep learning about being brave. You have to learn it over and over . . . You will have to make yourself into something beyond anyone's capacity to imagine you.'

Felicity Smith is a Voorstand emigre, wholeheartedly committed to political art in her adoptive Efica, through the workings of her faintly Brechtian theatre, the Feu Follet. It is into this marginal bohemia that she brings her child, and there that he is raised with not one but three fathers, an unreliable actor named Bill Millefleur, who forsakes Efica for the glitz of the Voorstand Sirkus; a married politician named Vincent Theroux, whose aesthetic sensibilities are grossly offended by Tristan's deformities; and Wally Paccione, a former thief who provides the closest thing to paternal consistency that Tristan ever knows. But Felicity is the primary force in Tristan's life, and he is marked by her assassination (by Voorstand's secret police) and absence as much as by her advice.

When, in the second half of the novel, Tristan sets off for Voorstand with Wally and his minder, it is intended to be on a Sirkus Tour, a passive consumption of Voorstander art. But their picaresque adventures lead to Tristan's appropriation of the nation's most powerful icon, Bruder Mouse. For the Eficans, it is a political act with complex implications.

Carey's novel is extremely impressive, and it develops an engrossing and thought-provoking narrative. But it is a dark, dense book, with little of the easy charm of, say, Oscar and Lucinda (it is difficult, initially, to be charmed by the mangled and snivelling Tristan). And while the invention of Smith's surroundings, at once alien and familiar, is intellectually necessary to the power of the novel, it risks distracting or even deterring less determined readers. That would be a shame, because the plucky Tristan ultimately sustains the faith and the affection of those who do persist. That he does so is a tribute both to Carey and to the preoccupation with the power of invention which so permeates his art.