The Parts. Keith Ridgway. Faber and Faber. UK £10.99, PB

Despite the achievements of a century of writing from Joyce through James Plunkett to Roddy Doyle, it seems that every few years yet another Irish novelist determines to take on the capital city, not just as the location for a story but as a participating character in itself.

The latest contender is Dublin-born London resident Keith Ridgway who, still in his mid 30s, and with only his second full-length novel, has already produced a convincing and all-too credible version against which many others will, so to speak, pale.

Though for many of its citizens the greatest change in recent times has been in the ethnic make-up of the city, Ridgway's Dublin seems less concerned with outside influence than it is with the continuing gap between the haves and have nots. In that sense, this is very much a post-Celtic Tiger novel, though one which prefers sexual politics to politics per se.

Focusing on six characters (the only outsider among them being a dapper but sinister American doctor), Ridgway waltzes the reader in and out of at first parallel then gradually interconnected narratives, always playing with the idea of the many cities inside of the one.

From the widowed and fabulously rich Delly Roche, confined to bed in her veritable mansion where she waits for death to take her, to Kez, a self-described Rent Boy selling himself via mobile phone, The Parts is not afraid of either grim or sexually frank subject matter. The fact that Delly ponders the cultural significance of her deceased husband's collection of eastern erotica while Kez daily risks his life in all-too real brief encounters adds irony, and no little comedy, to a mix that might be described as Gothic-flavoured social realism.

More than anything else, though, it is the power and lyricism of the writing that distinguishes this novel and makes it feel, to risk the cliché, so much more than the sum of its parts. From a flowing, present tense opening that might have led into Dylan Thomas' Under Milkwood, through everything from stripped back screenplay-like dialogue, chat room inanities and text messaging, Ridgway constantly shifts prose gear to match the twists and turns of events and to give a sense of characters, for all their proximity to each other, set apart from each other.

In alternating sections the narratives unfold, with the ultra vulnerable Kez squeezed in as a kind of running footnote to the other stories, segregated even by the typeface used. For a youngster who has noticed that people shake his hand only when they want to save him, this seems entirely appropriate, and shows how the much-praised author of 1998's The Long Falling can match technique to meaning in this ambitious, sometimes unsettling but hugely entertaining book.

© copyright Pat Boran