BOOK REVIEW / Shockwaves in the lagoon: 'Dead Lagoon' - Michael Dibdin: Faber & Faber, 14.99

IMAGINE YOU are the marketing manager of Faber & Faber. Your brief is to design a book of fiction to capture a good chunk of the upmarket leisure sector. The target readership are those who take their summer's lease of a Tuscan villa or go on citybreaks to Rome or Venice. Or indeed those who wish to evoke the magic of Italy while stopping at home. Whom do you turn to, to write the dream script? Who else but Michael Dibdin?

Dead Lagoon is the fourth of his thrillers starring the Venetian detective Aurelio Zen. In it, Dibdin tells a rollicking good tale that you want both to read fast, because of its gripping storyline, and to linger over, to savour the evocative descriptions of place and mood. His setting - the Dead Lagoon of Zen's home city - is more than a locus delicti. Rather, it is the location for a vivid and authentic account of the shockwaves and eddies caused by the massive upheavals Italy is currently undergoing. It is a sad indictment of the shortcomings of journalists that no newspaper articles have captured so poignantly the uncertainties of the country in transition.

Dibdin is our most perspicacious observer of Italian mores. He does not use Italy merely as a backdrop, but exploits his stories as a vehicle to convey his pictures of the contemporary scene. Whether adumbrating the archetypal relationship of Zen and his ageing mother, or the moral cowardice (or political astuteness, depending on your outlook) of senior civil servants, he describes human interaction which is characteristically Italian.

Zen goes back to Venice to investigate the disappearance of a wealthy American businessman. It is not a police job - or at least, he is not officially on the case. Although he is a senior police officer in Rome, he has agreed to take on a freelance piece of private sleuthing for the lawyers of the deceased. He undertook this task partly as a favour to his ex, Ellen, but mainly to help obtain the wherewithal to set up Tania, his current 'Lover? Mistress? Partner? Part of the charm of their relationship was that it eluded definition.'

Our hero is not without a few human failings. He is not strictly venal - he showed in earlier tales that he could not be bought, but was prepared to bend the rules to make a bit on the side - and to have a bit on the side too, for faithfulness was not one of his strong suits either. At first he resisted Ellen's entreaties. 'It's strictly illegal for a state employee to engage in secondary paid employment,' he pompously declaimed. She understood him - and the system - too well. 'Oh, come on Aurelio. You guys only work mornings anyway. Plus the money could be paid into a Swiss bank account.'

Zen's search for the missing businessman leads to a complex tale of drugs smuggling, bent policemen, shady boat owners, and ambitious local politicians. From the opening scene, set on the cemetery island of the lagoon, we realise that life - and death - are never as they seem, and that truth is as at best an approximation, shrouded in shifting layers of mystery and deceit.

The political context provides an unsettling backdrop for this tale. Nor does Dibdin ignore the recent changes to the criminal justice system in Italy. The old order is in disarray, embroiled in corruption scandals. New, ominous political forces are at work to fill the vacuum. Fact and fiction are seamlessly joined. Real people have walk-on parts in this portrayal of a city where the local demagogue - his sensual wife, a childhood acquaintance, stirs Zen's loins - hopes to revive the Venetian republic. The centre has collapsed, he argues. Rome no longer holds sway. Power now lies on the periphery, in city states like Venice. The city should be seeking new alliances with the lands of its historic area of influence, in the old Venetian empire along the Dalmatian coast, in the ex-Yugoslavia.

Zen is unimpressed by this appeal. But in time he realises there is some truth in the idea that every Venetian, even one so deracinated as himself, has to be either with the new separatist political movement or against it: there is no other choice. It is a challenge by the new order to take sides. This is something which, in his past, Zen had tried to avoid, in order to survive the shifting alliances at the top which could, and frequently did, stifle investigations or block promising careers if an officer was not in some way beholden to certain political interests. As he prepares to leave the city to return to Rome, he argues that Venice is his city too. Yet he remains ambivalent. For he also realises that the new populist political culture is so alien to his way of thinking that he still feels a stranger there.