Three authors in search of a body; THE BLACK BOOK by Orhan Pamuk trs Guneli Gun, Faber pounds 14.99

AT FIRST sight Orhan Pamuk's new book, his second to be published in English, fits neatly into the category of mystery. Galip, a lawyer living and working in Istanbul, is devastated when he comes home from work to discover his wife has disappeared, leaving behind an ambiguous note which sheds no light on her motive or whereabouts.

When Galip realises that his cousin Jelal, a celebrated newspaper columnist, has also gone missing, the plot takes on the hue of a classic family tragedy; Jelal and the absent wife, Ruya, are half-brother and sister. Inventing a cover story for his anxious family - Ruya is unwell, he says, then on holiday - Galip sets about tracking down the delinquent pair.

He does not do this by the standard detective story method of investigating clues and interviewing witnesses. Instead, convinced that the truth behind both disappearances lies in Jelal's writing, he immerses himself in the columnist's life. Half the novel consists of Jelal's newspaper columns, beginning with an elegant fantasy prompted by a news item about the falling water level of the Bosphorus; in one of many stunning evocations of Istanbul, Pamuk/Jelal imagines the accumulated detritus of half a dozen competing civilisations suddenly laid bare on the sea-bed.

A more obsessive side to Jelal's personality soon emerges in the shape of thousands of photographs with enigmatic markings, all of them stored in one of the journalist's several secret hideouts in the city. Galip also stumbles across his cousin's bizarre correspondence with readers - lengthy exchanges of letters in which he discusses impending military coups, the signs he claims to have read in people's faces (hence the photographs) and even the imminent coming of a Messiah.

Pamuk is formidably well read and there are sly parallels with other novels which revolve around conspiracy theories, notably Eco's Foucault's Pendulum whose characters manifest an obstinate (and apposite) determination to solve mysteries stretching back to the Crusades. Another obvious influence is the Arabian Nights, whose model of convoluted, unfinished tale-telling Pamuk sometimes adopts as Galip warders disconsolate through the streets of the ghostly snow-lined city.

But it becomes apparent, as The Black Book progresses, that these superficially beguiling secrets are a mask for a much more disturbing inquiry. Galip begins to question his unthinking hero-worship of his older cousin and a vital component of his own identity is undermined; the fact that the threat of disintegration existed long before his wife's disappearance is signalled by a simple linguistic device, the revelation that her name, Ruya, is also the Turkish word for "dream".

Much of the book passes, in fact, in a dreamlike state. Galip seizes and discards signs and clues, absorbing himself in Jelal's life to the point where, his own identity shattered, it seems natural to impersonate the missing man - even giving a TV interview to a British film crew as though he were Jelal. Early in the novel Galip observes that "the only detective novel worth reading would be one in which the writer himself didn't know the identity of the murderer", and of the three "authors" in The Black Book - Galip, Jelal and Pamuk himself - this is certainly true of two of them.

We are left with the possibility that Galip's inept interventions in Jelal's affairs are somehow responsible for the violent deaths at the end of the book - but it is no more than a possibility. This bizarre, dazzling novel turns the detective novel on its head, dislodging murder from its iconic status as the final mystery, and establishes Orhan Pamuk as one of the freshest, most original voices in contemporary fiction.