Updated tales tend to suffer from the archness that led Kipling to inveigh against "painty-winged, wand-waving, sugar-and-shake-your-head set of impostors". It is a pity he was not around for Herbie Brennan's brilliant Faerie Wars, a crossover title from which few readers of any age would wish to cross back.

Mixing a contemporary plot with another, often brutal world of beleaguered emperors, malign demons and unreliable faeries, Brennan writes with all the dash of an Irish storyteller at the peak of his form. Inventive as Harry Potter, dark as Gormenghast and as intelligently probing as Philip Pullman, here is a title to brighten the dreariest of winter days.

The book starts with the discovery by 14-year-old Henry that his mother is having an affair with his father's female secretary. We cut to Pyrgus, the unruly son of the Purple Emperor, noble if unbending leader of the faeries of the light. Both boys meet through a portal that provides access from one world to another.

While Henry's problems are domestic, Pyrgus is up against appalling villains, from Silas Brimstone, the part-owner of a glue factory with a dark secret, to Lord Hairstreak, the ruthless leader of the opposition. Beleth, the Prince of Darkness him-self, also has his eye on the young prince.

Pyrgus comes in for some severe punishment, and there is no shortage of graphic violence. But Princess Holly Blue, Pyrgus's sister, is on hand to suggest other ways of solving problems, through intelligence and a more subtle courage. Unlimited melodrama in contemporary writing often ends up choking on its own rhetoric, but Brennan avoids this by infusing his story with affectionate irony as characters are brought down to earth by humour. When Silas Brimstone is told by Beleth that he has to eliminate Pyrgus, his response is anything but Tolkienesque: "Piece of piss!"

Despite moments of serious intent, this is a story intended to entertain rather than convert: fluent, self-confident, sometimes garrulous but always transfixing. By linking domesticity with the vastness of a hidden world, Brennan brings into his fiction the sort of imaginative leap common in adolescent fantasies and, very often, well beyond into adulthood. At 368 pages, his novel is still not long enough: read it, and enjoy.