Photographs by David Degner

It was after 10 p.m. on July 8, 2009, when Sandra Mansour answered her cellphone to the panicked voice of her daughter-in-law, Nasreen. A week earlier, Nasreen and her husband, Naji Mansour, had been detained in the southern Sudanese city of Juba by agents of the country's internal security bureau. In the days since, Sandra had been desperately trying to find out where the couple was being held. Now Nasreen was calling to say that she'd been released—driven straight to the airport and booked on a flight to her native Kenya—but Naji remained in custody. He was being held in a dark, squalid basement cell, with a bucket for a bathroom and a dense swarm of mosquitoes that attacked his body as he slept. "You have to get him out of there," Nasreen said. But she was unfamiliar with Juba and could only offer the barest details about where they'd been held. "He's in a blue building. You've seen it. It's not far from your hotel."

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Sandra remembered passing a blue warehouse ringed by tall, razor-wire-topped fences. She hung up and turned to her daughter, Tahani, who'd flown to Juba to assist in tracking down her brother: "We've gotta go look for Naji." They packed food, water, and bug spray in case they found him. Then Sandra and Tahani laced up their sneakers, retrieved a flashlight, and slipped out onto a pitch-dark, deserted road.

Sudan's long-running civil war had ended a few years earlier, and Juba, once a malarial backwater on the White Nile, was poised to become the capital of the world's newest nation, South Sudan. The city had grown into a boomtown, its expansion fueled by newly discovered oil and an influx of foreign aid. Shacks and half-built concrete structures lined its maze of narrow, trash-strewn streets, and entrepreneurs rented out converted storage sheds for as much as $100 per night. Sandra, a US government contractor, lived in one of them.

The upstart city had a Wild West atmosphere. Rifle- and grenade-wielding bandits occasionally stormed poorly guarded compounds, and violent muggings and carjackings were commonplace. It was not safe to drive after dark, let alone walk, but Sandra and Tahani were desperate. "It was a very crazy thing to do," Sandra later recalled. "But it was the first lead we had, and there was nothing that was gonna stop us.

http://www.motherjones.com/politics/2014/05/sudan-fbi-informant-naji-mansour-terrorism