BOOK REVIEW / A vision of heaven in shell-suit grammar: 'Now you Know' - Michael Frayn: Viking, 14.99 pounds

THE Oxford Book of Yobs can't be far away. Everyone seems to be at it now, insinuating the loose, cunning drawl of low-life into their high art. You can see the attraction - slip in the shoulder pads of a set of quotation marks and the most fastidious novelist can swagger and cuss, can for once show the muscle of the prose as well as its mind.

For the first few pages of his new novel Michael Frayn seems to have been seduced, too, by shell-suit grammar and cocky mouthing. 'Always someone bursting to tell,' says his confiding voice, taking us on a tour of the exteriors of government offices. 'It's the pressure. Like the garden hose. Put your finger over the nozzle and what happens? It pisses over the back of your trousers.' But who is the beneficiary of these leaks and spurts? A tabloid journalist? A professional blackmailer? In fact, though Terry has a prison record and his relationship with the law is still adversarial, he will, for most readers, count as one of the angels.

Terry runs Open, a pressure group dedicated to nipping at the ankles of secretive government agencies. Crammed into a poky office with Shireen and Liz and Jacqui and Kent and Kevin, he works the levers of press releases, media interviews and publicity stunts, making mischief and a reputation that gets him recognised on the street. He has been described as a dangerous extremist at one Tory Party conference, but declares himself to be in favour of moderation, by which he means a sort of cheerful opportunism. He combines passion for his job with an amiable, never-mind temperament, a mix which Frayn manages to make both convincing and charming. Terry doesn't even have problems negotiating that notorious assault course for the liberal conscience, the importunities of the homeless girls who camp in his office doorway.

Naturally this equable voice will have to falter. The challenge comes in the form of Hilary, a young Home Office civil servant who first loathes Terry, then makes love to him, then leaks him photocopies of an internal report on a scandal over police brutality. She is a born-again whistle-blower, her conversion partly effected by a set-piece speech from Terry about heaven ('This is how I see it, Hilary: like all those office blocks made of gold reflecting glass, the sort where the people inside can see out, but the people outside can't see in. Only in heaven you can see in as well as out. A golden light in all the rooms. Nothing hidden. Everything visible.'), and partly by less tangible personal longings.

Hilary's mind is an open book to the reader, as are those of all the characters, laid bare in a succession of monologues which make up the novel. The technique seems only that at first - a means to cut between tones and colour of voice, but it demonstrates its real ingenuity towards the end, by which time Frayn has constructed a snare out of the mutually incompatible candour of his characters. Everyone in the Open office has a little (or not so little) secret which is finally exposed in a blackly funny office row. The desire for a world without secrecy is seen to be as fanciful and potentially destructive as the dream of a world without friction.

If this sounds a little diagrammatic, it is always rescued by Frayn's acute ear, which hears every awkward echo in casual cliches, and his wonderful ability to expose character through plots so intricately crafted that you might think they were the sole purpose of the novel. The master farceur who conceived Noises Off is at work here for darker, more humane purposes.