Back in the mid-1990s I lived for two years in the Pakistani city of Lahore, where I wrote for local newspapers and did ethnographic fieldwork for my dissertation on the urban Punjabi class system. Lahore is Pakistan's oldest and second-largest city after Karachi, about a thousand miles to the south on the Arabian Sea.

From an American perspective, you might loosely compare Lahore to Boston and Karachi to Los Angeles. Lahore is smaller, older and more self-consciously "cultured". It once served as a royal capital of the Mughal empire, and was the only major Indian city to join Pakistan at Partition. It's the political heart of Pakistan as well as the capital of Punjab, the country's richest and most populous province. Lahoris tend to be insular, a bit snobbish, and fiercely proud of their ancient urban heritage. As the Punjabi saying goes: "He who hasn't seen Lahore is yet unborn." (Jinnai Lahore nai vekhya oo jamia hi nahin.)

Karachi is something else entirely, a sprawling megalopolis of 18 million people that attracts immigrant strivers from all over the country. Karachi is Pakistan's only major port, its business capital, and also a locus classicus of urban dysfunction. Most Americans know it as the city where Wall Street Journal reporter Daniel Pearl was kidnapped and later beheaded, nearly a decade ago, by terrorists affiliated with Al Qaeda.

If Lahore is a city of ghosts and memories, Karachi is the dystopic future of urbanism, a cautionary tale told in crumbling concrete, raw sewage, grinding poverty and inescapable violence.  And it's the subject of NPR journalist Steve Inskeep's engrossing new book, Instant City: Life and Death in Karachi.

Not unlike Joyce's Ulysses, Inskeep's book captures a day in the city from many different perspectives.  On December 28, 2009, an anonymous bomb blast rips through a procession of Shi'a Muslims participating in the annual rite of Ashura, when Shi'as mourn the killing of the Prophet Mohammad's nephew Hussein by soldiers of the rival Sunni sect at the battle of Karbala in Iraq. The bomb kills more than thirty people, wounds hundreds more, and destroys a nearby shopping arcade.

In a chilling detail, one of many in this carefully reported book, we learn that the bomb was planted in a large metal box containing a slot through which people are supposed to drop damaged Korans, so that the holy text will not be trampled underfoot. In short, an object designed to protect Islamic scriptures becomes a vehicle for the mass murder of Muslims.

As with most such atrocities in Pakistan, we'll never know for sure who planned the Ashura bombing.  Karachi police eventually arrest four members of an obscure Sunni militant group called Jundallah and charge them with the crime, but all four escape from custody before they can be tried. The factual vacuum immediately gets filled with conspiracy theories. Some theorists accuse the Pakistani government. Others blame the CIA, and still others finger local real estate developers whose real goal was allegedly to destroy the shopping arcade and replace it with a more valuable structure.

On this grim foundation, Inskeep constructs a rich, fast-paced narrative about how Karachi grew from a sleepy fishing port to the sprawling global city that it is today. Like other "instant cities" around the world, modern Karachi is the product of rapid, massive migration in the decades following World War II. After the partition of the Indian subcontinent in 1947, mainly Urdu-speaking Muslim refugees poured into the city from other parts of India, overwhelming the native Sindhi population and creating the city's first great ethnic divide. Since then migrants have arrived from everywhere in Pakistan. Because the local government is generally corrupt and ineffectual, Karachiites tend to depend on ethnic and sectarian organizations for support and protection, a dynamic that explains much of the city's persistent strife.   

Although Karachi may be a uniquely troubled town, it has much in common with hypercities across Asia and the rest of the world. Inskeep writes: "No one metropolis could capture the full variety of the world's growing cities, but Karachi is representative in several ways. It's on the Asian coastline, where massive urban growth is under way. Its modern foundations were laid during the age of European colonialism. Its great expansion coincided with the postwar collapse of empire, when industrialization attracted people to the city—as did the desperation of people seeking shelter from political or economic catastrophes."

Despite its extravagant problems, Karachi is also a city of considerable charm, an aspect of the place that Western media coverage tends to neglect. Inskeep is a clear-eyed but sympathetic observer who brings Karachi to life by telling stories about the people who live there and, somehow, keep the city going. We meet the extraordinary Abdul Sattar Edhi, a former pharmacist whose Edhi Foundation operates a fleet of ambulances that pick up the wounded and the dead after atrocities like the Ashura bombing. We meet the grieving family of a pious Shi'a man who achieved his dream of marching at the head of the great Ashura procession, which was also the epicenter of the explosion that killed him. We meet the brave woman doctor who runs the emergency room that receives the wounded from Edhi's ambulances, until a second bomb explodes at the entrance to her hospital.

Hovering over the story is the ghost of Pakistan's founder, Mohammed Ali Jinnah. Karachi was Pakistan's first capital, and Jinnah moved there from Bombay at Partition, like so many other Muslims from across India. Jinnah's vision for Pakistan was that it should be a secular, democratic state where the Muslim majority would live in peace with their Hindu, Christian and Parsi brethren.

Jinnah died soon after Partition and long before his great dream started to crumble. Today Pakistan's many fault lines are most visible in its greatest city. Even so, Pakistanis keep right on moving to Karachi, dreaming of a better life. Some of them die and many more are disappointed, but their dreams survive. In that sense, Inskeep captures a human truth that applies far beyond Karachi.