In November 2006, I returned to live in Morocco after an absence of many years. Instead of staying in Rabat, my hometown, where family and friends could drop in at any moment, I rented a flat in a high-rise building in Casablanca, where I could write uninterrupted. From my living room window I had a full view of the King Hassan Mosque, a gleaming edifice that reportedly cost nearly $1 billion, enough to pay for more than a few schools or health clinics. On one side of the mosque, I could see the Lycée Lyautey, a private French institution attended by the children of the country’s elite. And on the other side of the mosque, though hidden from view, were the slums of Lahjajma.

Slums in Casablanca crop up when you least expect them—you could be rounding a corner from an extravagant health spa or an Art Deco building, and there, hidden behind a white wall, you’ll see clotheslines and satellite dishes, or hear children playing and quarreling. The karian, as the slums are known, take their name from the oldest of them, the Carrières Centrales, established early in the twentieth century by quarry workers who were expanding the port during the French occupation. Because this original karian was settled by transplants from the countryside, slum-dwellers in Casablanca are still viewed as outsiders, uncouth and uneducated, even when they have lived in the city for three generations.

During the year I spent in Casablanca, I noticed that slums were discussed in the press almost exclusively with the vocabulary of pathology. The karian were “dangerous.” They were places that “tainted” the city and had to be “eradicated.” One journalist called them “a gangrene”; another urged a “hunt for the slums.” The language became even more antagonistic after a failed terrorist attack in March 2007, when it was revealed that one of the suicide bombers, like those who had attacked the city four years earlier, had come from the slum of Sidi Moumen. I remember vividly a television reporter shoving a microphone in a woman’s face in Sidi Moumen and demanding to know why “your” youths did what they did.

I tell you all this because I want to explain why Katherine Boo’s first book, Behind the Beautiful Forevers, struck me with the force of a revelation. Unlike other reporters, who come to the slums in brief and harried visits, only when they have news to report or statistics to illustrate, Boo, a staff writer at The New Yorker, has chosen to chronicle the lives of slum-dwellers in the Indian city of Mumbai by spending more than three years with them, patiently listening to them talk about their aspirations, their struggles and their dilemmas.

Here is one dilemma, all the more disturbing for its banality. Fatima Sheikh, a crippled woman, lies on a bed in Burn Ward Number 10 at Cooper Hospital in Mumbai, an IV bag and a used syringe sticking to her skin. Abdul Hakim Husain, the teenager who is accused of pouring kerosene over Fatima’s body and setting it alight, is in the custody of officers from the Sahar Police Station. After assessing the situation, Asha Waghekar, a part-time schoolteacher and full-time fixer, makes what she deems a very fair offer: Abdul Hakim’s parents can pay her 1,000 rupees and she will persuade Fatima to drop the charges.

That crime, justice and money could be so intimately and immediately intertwined may strike the reader as just another instance of corruption, easily diagnosed and just as easily condemned. “In the West,” Boo explains, “and among some in the Indian elite, this word, corruption, had purely negative connotations; it was seen as blocking India’s modern, global ambitions. But for the poor of a country where corruption thieved a great deal of opportunity, corruption was one of the genuine opportunities that remained.” In the case of Abdul Hakim Husain, who is wholly innocent of the crime, the bribe represents his best chance at a quick and painless acquittal. He never hears about it, however, because his mother, Zehrunisa, encouraged by an officer’s initial kindness and distrustful of her neighbor Asha, turns down the offer.

This refusal launches a conflict that will touch the lives of the accuser, the accused and the fixer, already bound together by the place they call home: the slum of Annawadi, only 200 yards from the road leading to Mumbai’s International Airport and its glitzy hotels. In Annawadi, as elsewhere in the world, people have dreams and ambitions, which they believe to be “properly aligned to [their] capacities.” They speak of better lives casually, as if, Boo writes, “fortune were a cousin arriving on Sunday.”

* * *

Thus the Husains have dreams of leaving Annawadi, where they are one of only a few Muslim families. They buy garbage from waste scavengers, sort it and resell it to a recycling plant. Their eldest son, Abdul Hakim, is 16 (or perhaps 19; the family isn’t good with dates). He has to do all the work because his father, Karam, has tuberculosis. Mirchi, the 14-year-old, goes to school, and someday, perhaps, with a bit of luck, someone might overlook his Muslim background and hire him as a waiter at one of the airport’s posh hotels. The other nine children, including the 2-year-old, whose face is marked by rat bites, are all invested with similar hopes. Before the incident with Fatima, the Husains put a down payment on land in Vasai, just outside Mumbai, the first concrete step in their plan to leave Annawadi.

Next door to the Husains lives Fatima Sheikh, whom everyone calls the One Leg. She has a husband, three children and a string of lovers, whom she keeps not because of money—something Annawadians might have forgiven—but for the simple pleasure of feeling wanted. Above all, Fatima the One Leg wants “to transcend the affliction by which others had named her.” Because her husband earns only $2 sorting trash for fourteen hours a day in a different slum, Fatima grows jealous of her neighbors’ upward mobility. It is not a coincidence that the event that precipitates the main story—the burning of Fatima in her hut—happens on the day that the Husains are installing floor tiles and a cooking shelf in their tiny home.

Then there is Asha Waghekar, an ambitious high school dropout and part-time kindergarten teacher who lives by the public toilet. She has dreams of her own too, but they do not involve leaving the slum of Annawadi so much as rising above it. She has thrown her lot in with the Hindu fundamentalist group Shiv Sena, and she hopes one day to become a slumlord—an unofficial position, but one that police officers and politicians deem necessary in order to “run the settlement according to the authorities’ interests.” Asha’s daughter, Manju, attends a liberal arts women’s college where the reading of books is not a requirement. Manju is merely expected to memorize plot summaries, a process she calls “by-hearting.” One day she hopes to become Annawadi’s first female college graduate.

By Indian standards, Annawadi is a very small slum. It is home to only 3,000 people, packed into 335 huts. For some time, the slum was hidden from street view by a concrete wall covered with ads for Italianate floor tiles. The corporate slogan read: Beautiful Forever Beautiful Forever Beautiful Forever. There is a sewage lake, where building contractors dump their garbage, and where pigs and dogs roam, their bellies stained blue by the water. The air, filled with the smell of waste, is so filthy that Abdul Hakim’s snot has long ago turned black. And there is the constant threat that the Airport Authority will seek to reclaim the land on which Annawadians squat. By working on this relatively small scale, Boo gives the reader a more intimate picture of how political and economic decisions made in government offices and corporate boardrooms can affect the lives of ordinary people in India.

In Annawadi, nearly everything falls under the law of the free market. If you want it, you have to pay for it. Water? There are six public water faucets, but a Shiv Sena gang has appropriated them and charges usage fees. An education? The free municipal school near the airport stops at the eighth grade, and the teachers are often absent anyway. If you want to attend the ninth grade, you have to pay for a private school. A new heart valve? The public hospitals are supposed to perform these kinds of operations for very little money, but the heart surgeon at Sion Hospital thinks it’s worth 60,000 rupees.

One might retort that this is corruption, not the free market. But such a distinction is possible only when we remove the laws of trade and competition from certain aspects of our lives and agree that a price cannot be put on them. In the past twenty years, however, many national economies have undergone an extreme liberalization that has blurred this distinction. India, for instance, abandoned the redistributive policies that had characterized its economy since independence and in 1991 began a process of economic reform that included privatization, deregulation and an increased reliance on technology and urban-centered services at the expense of agriculture.

As a result, the Indian economy grew at a stupendously fast rate, while people from the impoverished countryside began to flock to the cities in search of work. This was the case with Annawadi, which was initially settled by Tamil migrants brought in to repair an airport runway. Though the “undercity” of Annawadi is now home to people of many different backgrounds, the vast majority of them do not have the language skills, education, social connections or caste privileges that might enable them to find stable work in the “overcity” of Mumbai. The number of Annawadians who have permanent jobs is six; all the others make do with part-time work or informal jobs, like scavenging waste. But turning waste into a commodity isn’t enough to sustain the entire undercity—other commodities must be found. And with some ingenuity and entrepreneurship, nearly anything can be turned into a marketable item and sold at a profit.

If it sounds like unbearable economic Darwinism, that’s because it is. The anti-poverty programs that Boo mentions in the book appear to be failures—the program benefits are simply auctioned off to the highest bidder. For instance, Asha and some of her friends benefited from a program that “was supposed to encourage financially vulnerable women to pool their savings and make low-interest loans to one another in times of need. But Asha’s self-help group preferred to lend the pooled money at high interest to poorer women whom they’d excluded from the collective.” Religious charities don’t fare much better. Sister Paulette, who runs the Catholic orphanage, routinely sells expired food donated by airline-catering companies to poor people in Annawadi, who in turn try to resell it in order to derive a small profit.

In this context, it’s not hard to see that if you want a bank loan, you have to pay for the privilege of having your application chosen. It’s not hard to see how a new caste certificate, a new birthplace and a new set of ancestors can be arranged for upper-caste Indians in order to guarantee a place on a ballot reserved for low-caste candidates. And it’s certainly not hard to see why court witnesses and police officers would want money for a verdict of innocence. These are merely ways of making a living in a place where “the infrastructure of opportunity” is limited.

* * *

Having ushered us into the slum of Annawadi, Boo makes it hard for us to leave. It is Boo’s great achievement that, even as injustice after injustice takes place on the page, Annawadians never become clichés of third-world abjectness or walk-ons in a piece of blockbuster poverty porn like Slumdog Millionaire. In her author’s note, she explains that, though she spent three years interviewing people in the slum, she has chosen to keep herself out of the story, adopting an omniscient point of view that allows her to report Annawadians’ actions as well as their thoughts and feelings. To reconstruct the events that led to the burning of Fatima the One Leg, Boo interviewed 168 people, some of them more than once, and consulted more than 3,000 public records. She also asked some of her subjects to document their lives with Flip cameras, thus giving them the freedom to choose their own narratives.

Boo succeeds where so many reporters have failed because she has given the people of the undercity the same time and attention they would have received had they been residents of the overcity. And it is to her credit that she never suggests policies for helping Annawadians out of poverty; her concern is how existing policies have affected them. Her superb sense of detail, her nuanced writing and her considerable empathy make Behind the Beautiful Forevers nothing short of a masterpiece.

It might be tempting to think that what happens in Annawadi can only happen in the developing world. But in Los Angeles, where I live now, I see migrants every day going through the trashcans in the alley behind my house. They pick out tin cans, glass bottles and plastic containers of every kind, which they sort and sell at the recycling plant. These migrants too have come from another part of the continent; they too have settled in an undercity; and they too are dependent for their survival on the overcity.