Ludmila's Broken English, by D B C Pierre

If writers were athletes, then DBC Pierre would be hanging out with the skydivers, the stunt-snowboarders and the white-water rafters. Pierre's high-risk prose explores and expands the cartoonish, taboo-busting outer edges of literary possibility. Vernon God Little, his gloriously black comedy of American trailer-trash manners, was a poignant drama of small-town loserdom in a gun-obsessed world, and a masterful piece of narration. Its greatest triumph was the strength of its 15-year-old hero's voice, bursting with a poignant rage that took it to a level almost beyond satire, yet still managed to convey both hope and heart.

In Ludmila's Broken English, Pierre opts for the more detached third person to tell two stories, one from Eastern Europe and one from the West, which he sets on a path of not so much convergance as fraught collision. Former Siamese twins Blair and Bunny Heath, institutionalised until medical intervention at the age of 33, have been released into the community. Intent on making the most of freedom now that their chests have been separated, the bickering duo spend their waking hours in long conversations with dodgy Cockney geezers in clubs, consuming full English breakfasts, lusting after local and foreign babes, and performing the tango - the only outward sign that they were ever a unit.

Meanwhile, in the desperate bullet-smacked region of Ublil in the former USSR, we meet Ludmila Derev. Ludmila belongs to a family whose unloveable members snarl Ubli phrases like "pelt a lash" and "cut your hatch", and who refer to one another as "spastic geese". Having murdered her lecherous grandfather as he attempts an anal assault, Ludmila finds herself catapulted into a rockily conceived exercise in damage-control, involving the sale of the family tractor. The resultant roubles stuffed safely into her knickers, Ludmila finds herself sucked into the flesh trade of the Big City.

Spotting her photo on the internet, Blair Heath, who has the lion's share of the fraternal testosterone, takes action. Dragging his "parasite" brother in his wake, he embarks on a journey into the unknown snowscapes of the East. But by the time the twins and Ludmila finally clap eyes on one another on page 250, whatever narrative momentum had been nudged into being has long since died a death.

When a climax of sorts is offered, a grisly and quite gratuitous bloodbath in which most of the cast get their brains blown out - the reader (and their creator, one suspects) is past caring about any of them. And when Ludmila finally gets to exercise her broken English, the whole novel has become so silted up with language that the plot seems almost a side-issue.

To be fair to Pierre, he sets the outlandish tone from the start, planting "omphalopagus" and "monozygotes" defiantly on page one, as if to warn the reader that the ride ahead may involve a dictionary, if not Paracetamol. Although there are moments of exquisite clarity, Pierre's prose seems to delight in scattering vocabulary - as Blair himself does - "like chunks of litter".

Vernon God Little was an energetic celebration of language. In Ludmila's Broken English, it feels as if there is almost a kind of devil-may-care vandalism at work.

For fans of Pierre's first novel, and I am one of them, the result cannot be anything but dismaying. Perhaps this failure was pre-programmed: the second novel is a notoriously difficult beast. How much more so it must be for a writer who has hit the jackpot of the Man Booker on his first attempt.

Or perhaps, more simply, that's the trouble with extreme lit. You hit or you miss. You succeed spectacularly, or you fail spectacularly. This time, the DBC Pierre barrel went over the falls, and did not pop up again. On the strength of Vernon God Little, if not of this novel, Mr Dirty But Clean is still a writer to believe in - but a whole lot less.

Liz Jensen's latest novel is 'The Ninth Life of Louis Drax' (Bloomsbury)