At the southern city of Hyderabad, a train branch line jutted into the desert, toward the border with India. This was Thar, a desert region where, unusually, Hindus are predominant. A rural commuter service — a train with open doors and a handful of seats — ambled through irrigated farmland toward the desert. On board were farmers, small traders and pilgrims returning from a Hindu shrine, the bareheaded women adorned in gold and silver jewelry.

At the district’s main town, Umerkot, the local colony of snake charmers lives in the shadow of a clay-walled fort. The chief snake charmer, wearing a bright red turban and playing a flute, entranced a cobra as it curled from a wicker basket. Later, he produced a government certificate that attested to his ability to “perform a dangerous act of passing three-foot snake from nostril and mouth.”

“Half of our people are in India,” he said afterward, pointing toward the desert and the border. “But we feel ourselves 100 percent Pakistani.”

Karachi: The Slum Patriot

Land is gold in Karachi, Pakistan’s tremulous port megalopolis: a city of migrants, filled with opportunity and danger, where space is at a premium that is often paid in blood. Political parties, mullahs, criminal gangs and Taliban militants all battle for land in the city, often with weapons. The railways offer an easy target.

Slums crowd the train lines that snake through the city, pushing up against the tracks. Migrants have been coming here for decades, seeking economic opportunity or, more recently, fleeing Taliban violence.

A short walk from Karachi’s main train station lies Railway Colony Gate No. 10: a cluster of rough shacks, pressed against a slope, bordered by a stagnant pool of black, putrid sewage.

Among its residents is Nazir Ahmed Jan, a burly 30-year-old and an unlikely Pakistani patriot.

Mr. Jan, known to friends as Janu, is from the northwestern Swat Valley, where fighting erupted in 2009. After the Taliban arrived, his family fled Khwazakhela, a village “between the river and the mountain,” which he described with misty-eyed nostalgia: lush fields, soaring mountains and his family’s grocery store, later destroyed in fighting.