Maass spent eight weeks in Africa—where a host of civil wars and regional disputes have given rise to the most ambitious and challenging aid projects on the globe—researching "Another Day in the Drop Zone," which begins on page 68. In rebel-controlled areas of southern Sudan, where Maass chronicled UN food drops supervised by a young American aid worker named Sienna Loftus, temperatures can hit 120 degrees, malaria is commonplace, and pro-government militias sometimes storm out of the bush on horseback. In Somalia, Maass documented the efforts of veteran relief worker John Miskell to deliver a food convoy to a remote town on the verge of famine. "Different clans are constantly fighting each other," Maass says of the mayhem that shadowed his reporting. "It's pure disorder. Violent disorder."

Why work in these inhospitable places? Why court such risk? For some, Maass suggests it is "the thrill of exotic altruism"—an almost addictive desire to be immersed in the adventure of relief work, with its daring improvisations and terrifying unpredictability. But for many, it's the chance to do something meaningful. "They feel they are making a life-and-death difference," says Maass. "That's something you can't get on Wall Street or in Silicon Valley."