In the land of the defeated and oppressed, <i> to be </i> is to be someone else : THE BLACK BOOK, <i> By Orhan Pamuk Translated from Turkish by Guneli Gun (Farrar, Straus & Giroux: $25; 400 pp.)</i>

Orhan Pamuk’s braided mysteries coil around the story of a plodding husband who searches for his restless wife through Istanbul’s serpentine streets and historical memory. Once it was the Ottoman Empire’s Constantinople and before that, the Byzantine Empire’s, and long before that, the ancient Greek Byzantium.

For Pamuk, author of the warmly praised “The White Castle,� the city is a suffocating midden of 2,000 years of temporary victories and permanent defeat. Pamuk writes of the defeat. His philosophical detective story is, in fact, an evocation of the crippled consciousness and destructive reflexes of his fellow Turks: heirs of a traditional Eastern society, and engaged for three quarters of a century in a Westernizing project that still has not taken root.

“In the land of the defeated and oppressed, to be is to be someone else,� asserts one of the many figures--at once enigmatic and hysterically overwrought--whom the husband, Galip, encounters on his week-long quest. It is the underlying theme of a book of disguises and transformations. Personal identity is unattainable when a nation’s identity has been lost, and in neither case--so goes Pamuk’s menacing comedy--can it be recovered.

Elaborated with a dizzying wealth of discursiveness, distraction and literary baiting and switching, it often bogs down under its own abundance. It will dazzle and then, with an effect akin to snow-blindness, it goes indistinct. It disappears into its own virtuosity and reappears. It remains distant from the reader like someone who talks fast and well and doesn’t look you in the eye, and suddenly, with disconcerting effect, looks you in the eye. It is a trying book and worth trying.

Galip’s quest is partly human and mostly allegorical. He is an undistinguished lawyer desperately in love with Ruya, his long-haired, long-legged cousin and wife, who spends the day reading detective novels. We never see her and yet--an example of Pamuk’s gifted elusiveness--she is vivid and oddly lovable.

She vanishes suddenly, leaving a 19-word note in green ink. We are only told nine of the words--an example of Pamuk’s exasperating elusiveness--but we are made to understand that she has gone off with her half-brother Jelal, to whom she has always been attracted. Galip comically hides the disappearance from his family. When his aunt phones he makes footstep noises to signal that he has gone to fetch her and found her asleep; then he sets off to try to track the pair down.

So much for the humanity, though it will return, movingly, at the end. In the quest, Ruya is all but lost sight of; the real quarry is Jelal. He is as brilliant as Galip is obscure: Istanbul’s most celebrated and controversial newspaper columnist. Galip has always worshiped and envied him and lived in his shadow. Even as children, when Galip and Ruya played hide-and-seek Ruya would never try to find him, but go off instead to meet Jelal.

The book proceeds by alternate chapters. One set tells of Galip’s search; the other contains Jelal’s writings. Gradually the two converge; finally Galip and Jelal will also converge. Eventually Galip will be living in Jelal’s apartment, wearing his pajamas, writing his columns and taking over his lovers’ calls and his death threats. By this time the actual fate of Jelal and Ruya has dwindled. Eventually we will learn it and be touched when Galip momentarily comes down to earth, as it were, and lets himself grieve.

The Galip-Jelal quest is a wild, varied and sometimes stupefyingly arcane trip through Turkish history and culture, political battles, themes of individual and national alienation, portraits of extravagant and emblematic characters and beliefs, and Galip’s own obsessions. He tramps the streets and neighborhoods of Istanbul as thoroughly as Leopold Bloom tramped Dublin; stopping frequently to eat. Eating--he buys from street stands and cafes and sticks to the cheap traditional dishes--is a way to assure himself that there is, in fact, a Turkish identity.

There is a bravura chapter in which Jelal writes of the Bosphorous drained, and sedimentary layers of history turning up in the pestilential muck. There are the skeletons of galley-slaves chained to their boats, the skeletons of crusaders atop their skeleton horses, sackfuls of the Sultan’s courtiers fallen out of favor, strangled and ditched, an entire German battleship and a white Cadillac belonging to a rich gangster. The gangster’s skull and his girlfriend’s are glued together in a kiss. Galip thinks for a moment of Ruya before returning to his intoxicating existential quest.

Wandering through the city he visits two of Jelal’s colleagues, each with his own mania. They question him fiercely, intrusively and outlandishly; Galip is like Lewis Carroll’s Alice undergoing impertinent questions from the likes of the Caterpillar and the Red Queen.

He visits Ruya’s first husband, an intellectual who has set himself against all foreign cultural influences and makes a point of living like a provincial middle-class Turk, with a doily over the TV and a dusty tray of cordials brought out for visitors. He visits the premises of a failed mannequin artist who had insisted on portraying authentically Turkish figures--bow-legged, short, mustached--instead of the blond anonymous elegance required by Westernized commerce. He is shown wax models of those the artist despised--writers and translators who import alien culture--and those he admired--police torturers whose careers suffered because they insisted on using traditional Turkish methods instead of newfangled methods brought in from abroad.

To be oneself, to reject outside influences: a national obsession that, for Pamuk, leads nowhere. He writes an allegory of a prince who sets his people an example by excluding anything that might dilute his own authenticity. He gets rid of his books (though then, finding his mind empty, he brings a few back). He gets rid of paintings, furniture, his wife. Not wishing to be influenced by memories, he banishes smells and music. Finally he dies in a room painted white; its only furniture a white piano. His last words are: “Nothing at all.�

Galip, however, illustrates an opposite national obsession. He wants only to be someone else; he wants only to be the powerful and glamorous Jelal, free of narrow Turkish prejudices and sought out by foreign journalists and television teams as their sophisticated interlocutor. He wants above all to have the power that Jelal wields: to control the universe by writing about it. By the end, he has to all intents and purposes become Jelal. As for the real Jelal: before a mysterious ambush that claims his and Ruya’s lives, he has shown signs of abdicating his power and seeking something more authentic.

What that will be, this intriguing, overnourished and maddeningly private attempt at a public novel, doesn’t say. It is neither retreat into national solipsism nor dilution in a homogeneous world culture. All we have to hold on to, at the end, is Galip remembering Ruya and the game they once played. They would try to describe what a day would be like when they reached the age of 73. Now, alone, Galip lives out that day in his imagination.