For as long as anyone can remember, the neighborhood known as Heera Mandi, tucked into the northern corner of the walled city of Lahore, Pakistan, has been a red-light district. The name means Diamond Market, but long before the British arrived in the mid-19th century it was already well established as a pleasure center, a place for Pakistani men to stray from their arranged marriages and spend time with beautiful women schooled in the arts of song, dance and seduction.

The old neighborhood, with its crumbling buildings, is on its last legs now. The fabled courtesans of Heera Mandi, once sought out by princes and emperors, are a distant memory, their role much reduced, like the geishas of Japan. Today's client is more likely to be a fat businessman flashing a Rolex and driving a Range Rover. The women, hastily trained, dance to music booming from a tape deck if they dance at all. Some are barely into their teens. Art has given way to pure commerce. "It was good in those days, but all that has changed," an old prostitute recalls. "Nobody bothers with singing and dancing anymore. We were trained for years, but today nobody does that."

Louise Brown, a British academic who studies the sex trade in Asia, spent seven years, off and on, living in Heera Mandi. "The Dancing Girls of Lahore" is her report, both chilling and heart-warming, on a neighborhood where all the rules seem to be changing except the ones that keep Pakistani women in a state of abject servitude.

Ms. Brown, author of "Sex Slaves: The Trafficking of Women in Asia," has a sociologist's eye and a novelist's appreciation of her surroundings and the human drama that plays out before her. She spends nearly as much time describing the street foods of Lahore and the excitement of religious festivals as she does analyzing the grim economics of the sex trade. Her main character, Maha, a prostitute on the downward side of her career, comes alive in all three dimensions, fully realized in the circumscribed world that has defined life for her mother, grandmother and great-grandmother before her. Prostitution, in Heera Mandi, is a family profession.

Maha, like Ms. Brown, has a nose attuned to the subtlest gradations of status. Her miseries and her triumphs depend on it. In her prime, like the rest of the women of the quarter, she commanded top prices. At 12, she was sold to a wealthy sheik in Dubai for a single encounter. Later she enjoyed the patronage of powerful, wealthy men, who, in Pakistan, are expected to keep multiple mistresses. Prostitutes refer to such clients as their husbands and, if lucky, can amass enough cash and gifts, while keeping several men on the string, to buy a comfortable retirement.

As the years pass, the clients become more numerous and less wealthy. Maha, in her 30's, overweight and shopworn after bearing five children, now depends on the uncertain charity of the feckless Adnan, an opium-addicted businessman who once set her up in a nice house outside Heera Mandi but more recently ordered her back to the old neighborhood. "I'm old and finished," Maha tells the author, who writes: "She's probably right. Maha's story is a common one: pretty women from Heera Mandi win a temporary reprieve from the brothel in their twenties only to return in their thirties. Maha has come back to the place where she was born and has always belonged."

The family fortunes look bleak, and Ms. Brown looks on in distress as Maha grooms her three daughters for the trade. In spare, eloquent prose, she explains the harsh rules of the game. Adnan was Maha's last chance. After he leaves her, a question of when rather than if, she will be hard-pressed to attract another patron. Her son cannot hope to marry respectably. Unless her daughters rise to the occasion, she could very well wind up in Tibbi Gali, the discount sex market, where older women sell themselves for as little as 20 rupees, the price of a bottle of Coke. The once-beautiful Maha, fiery and proud, still refers to herself as one of the " 'ten-thousand-rupee women' ($169)."

Ms. Brown perceptively analyzes this boast, often heard in Heera Mandi. By maintaining a prosperous front, prostitutes defend their price. They also, unwittingly, add to their own misery. Most of the women settle for less than 10,000 rupees but take the claims of their sisters at face value. "Women think it's only their own business that is bad, it's only they who cannot afford to pay the rent, it's only their own husbands who are cruel," Ms. Brown writes. "They don't believe me when I tell them that the lives of other women are equally blighted, and they say that I mustn't let anyone know of their own difficulties."

Maha is a fighter, and Ms. Brown renders her life in full, sensuous detail. It's all there: the long hours of boredom punctuated by vicious fights with her daughters and the neighbors; the search for solace in fattening foods and codeine-laced cough syrup; the firm belief in black magic and spells; the lurching mood swings from black despair to giddy hope. Perhaps the girls can find their way into films. (The neighborhood has produced many of Pakistan's movie stars.) Or perhaps Nena, Maha's most attractive, accomplished daughter, can find a pot of gold at the end of the rainbow on sex-junkets to the Persian Gulf states, or in the protective arms of a wealthy patron. There are no truly happy endings. But against all the odds, women like Maha somehow manage to make a life. Ms. Brown, astonishingly, makes that seem plausible.

Reprinted from the New York Times