Jeff in Venice, Death in Varanasi, by Geoff Dyer

If ever there was a book of two halves, it is this, Geoff Dyer's first novel for over a decade. His last fictional excursion (though for Dyer the division is largely artificial) was Paris, Trance, a druggy elegy for 90s romanticism that was partly a reworking of Hemingway's The Sun Also Rises.

Then, Dyer tipped his hat by repeatedly slipped lines from that novel into the text of his, as if trying to inject it with Hemingway DNA. He pulls a similar trick with Jeff in Venice, Death in Varanasi, though no prizes this time around for guessing his source material. Dyer's conceit is to filet the quasi-Eastern philosophy of renunciation at the heart of Thomas Mann's story and separate it out into two discrete narratives, that then intricately reflect and inform each other.

In the first part, discontented freelance journalist Jeff Atman (the last name references the Hindu concept of soul) is briefly lifted out of his usual round of junkets and meaningless think pieces when he is sent to cover the Venice Biennale.

It's a dazzling move. Venice, so often seen as the repository of a vanished past, is repainted as the ultimate in Western metropolitan excess - a shimmering canvas crammed with art world players and liggers. Trying to get into a party at the Peggy Guggenheim Collection, Jeff notes, "It was as if the government of Venice had fallen and the last helicopters were about to take off from the Guggenheim."

Whereas Mann's tragic hero, Aschenbach, is the model of a pious aesthete, Jeff is exuberantly shallow, belting back bellini after bellini, skimming the exhibitions and falling into a miraculous tryst with beautiful American Laura. In contrast to poor old Aschenbach's never-to-be-consummated desire for the teenage boy Tadzio, Jeff gets two great, characteristically uninhibited sex scenes.

In short, this whole section - 'Jeff in Venice' - is a love song to the pleasures of the phenomenal world. It's very fast and very funny, but under the ecstasy and the satire, it's not to hard to see the void beginning to open under Jeff.

The second part of the book, 'Death in Varanasi', comes with a sense of dislocation, not least because it switches from the third to the first person. In it, Jeff (let's assume it's Jeff, though it's never made explicit) flies to India to write a travel piece on Varanasi, the city on the Ganges that is the best place for a Hindu to die, as it effectively lets you to step off the eternal cycle of rebirth.

If the Venice section is all about desire, Varanasi is its opposite. Jeff files his piece, but decides to stay on, keeping himself aloof from the backpackers and crusties and letting the chaos of the place soak through him.

With no desire, of course, there is no need for plot, and the writing in the section is Dyer at his very best: philosophical, astute, unstructured, and continually oscillating between surface and depth, between the casual and the universal. From dozens of similar examples, how about this description of the ever-present hawkers, never striking up conversation without an ulterior motive:

"The masters of this art were like classical musicians, indefinitely extending the alap, elaborating and exploring the raga without precisely identifying it until its nature became clear - except, in this case, the raga was always the same: raga Boat, raga Rickshaw, both variants of raga Rupee."

Dyer keeps up the façade of Englishman-abroad grumpiness as long as he can, but 'Jeff's' consummation is unavoidable and, when it comes, quite beautiful. (I'd be very happy to die like Jeff, which is not something I've ever thought on closing a book before.) This might be one of Dyer's best books, but, the more he writes, the less the distinction between them becomes important. They are all a part of each other. To choose a favourite is somehow to miss the point.