The eunuch of Istanbul

In jason goodwin's historical thrillers, the main character is the turkish capital

Eunuchs have played a focal role in many a civilisation, their sexual "in-betweenness" giving them an intermediate social position wherein they were, at once, part of the society they inhabited and outside it.

No wonder, Yashim Togalu "" the protagonist of Jason Goodwin's The Janissary Tree, published last year to much acclaim, and now, The Snake Stone "" is the ideal detective, able to negotiate seamlessly between the high and the low, privy to state secrets because of his access to the sultan and valide sultan, and yet dispassionate, even philosophical.

But, if Yashim is the protagonist of Goodwin's novels, their hero, undoubtedly, is Istanbul "" "city of patriarchs and sultans, the busy kaleidoscope of the gorgeous east, the pride of fifteen centuries".

But this is the Istanbul of the 1830s when much of the pride and the glory are past; the Ottoman Empire is in decline; and its cosmopolitanism is under threat from the politically ascendant Christian West, on the one hand, and the rising parochialism of its many races and faiths, on the other.

In The Janissary Tree it was an abortive uprising by the janissaries set against the domestic drama inside the harem, while in this one, Goodwin weaves together the imminent death of the sultan and the resultant uncertainty, with the Greek problem and the mystery of the lost relics of Byzantium. Clearly, these are times, violent and desperate, when men kill easily, and brutally.

Like any good whodunit, corpses "" in various stages of degeneration and defacement "" turn up at regular intervals in The Snake Stone. But what's interesting is the clever way in which the city's culture and manners, topography and history are woven into the blood and gore, the plot itself.

So you have Maximillian Lefevre, a French archaeologist who comes to Istanbul with a 16th-century text with clues that might lead him to the Byzantine treasure, killed and his face half-eaten by dogs "" the "rough-coated yellow dogs with short legs, large jaws and feathery curving tails [who] spent most of the day lumped in all the alleys, gateways, thoroughfares and backstreets" "" a grotesquerie that is in fact a red herring.

Then there's Andre Xani, who plays a vital role as a corpse, floating in an ancient cistern, part of the intricate network of waterways that runs below the ancient city and feeds its many houses, fountains, his "entrails trailing".

But it's not just the more popular icons of the city "" the Suleiymaniye Mosque, the Aya Sophia, the serpent columns "" but also its more quotidian ones like its many cramped spice and vegetable bazaars, its caiques and little street-side kebab shops, its quaint guilds, that Goodwin brings to life, through some luminous writing and characterisation.

There's Yashim, of course, who is probably a better cook than he is a detective, but he's supported by an entire case of minor and major characters "" the down-and-out Polish ambassador Stanislaw Palewski, the stiff-backed valide sultan, the ageing kocek dancer Preen, even Widow Matalya, the Byron-obsessed British diplomat, Composton "" bring alive the plot with their quirks. Dr Millingen, the doctor who treated Lord Byron during his last days in Missolonghi, also makes an appearance.

The only time Goodwin falters, perhaps, is when he brings in a sexual, love interest "" Eugenia in the first book, and the lovely Amelie, Lefevre's wife in The Snake Stone. After all, a detective, at least in the classical Holmesian sense, seldom becomes a part of the emotional matrix of the plot "" he is best cast as its analyser, an observer.