Novels about animals are tricky acts to pull off. Anthropomorphism and sentimentality threaten to undermine the narrative if the author makes his characters too human, while a terminal case of so-whatness looms if he stays strictly in the realm of the feral. Perhaps this is why so few writers of adult fiction employ animals as their protagonists. In recent memory, only the she-wolf in Cormac McCarthy's The Crossing has succeeded as a credible and engrossing beast-hero.

Timbuktu, Paul Auster's first work of fiction in five years, attempts to inhabit this difficult narrative terrain. It tells the story of Mr Bones, a mongrel dog belonging to Willie Christmas, an 'outlaw poet prowling the gutters of a ruined world'. Master and beast spend half the year wandering America and the other half holed up in Willie's mother's New York apartment, where the poet scrawls doggerel verse no one will ever read and the mutt sleeps by the heater. It is a pretty good life for a dog, although Willie's tendency to lapse into madness since his 'schizo flip-out of 1968' makes for occasional hard times – 'whenever the pinball machine in his head speeded up and went tilt, all bets were off.' Mr Bones's existence is thrown into chaos when Willie contracts a terminal cough. Knowing his days are numbered, the delirious poet drags Mr Bones down to Baltimore, where he hopes to turn his care over to a fondly remembered teacher from his childhood. They make it no farther than the Edgar Man Poe museum, where Willie finally gives up the ghost. Knowing that he'd better find a new master if he's to elude death row at the city pound, Mr Bones takes up with Henry Chow, a lonely eleven-year-old Chinese-American boy.

They spend an idyllic summer wandering the strange city, until Mr Bones is discovered by Henry's dog-hating father, who also happens to be the proprietor of a Chinese restaurant. Having heard that dogs are likely to wind up on the menu at such places, Mr Bones reluctantly flees to Virginia,