But Sachs’s quest—which plays out in the handful of villages in sub-Saharan Africa that comprise his Millennium Villages Project (MVP)—seems to falter at every turn. A livestock market is abandoned two months after it opens. Villagers use their new mosquito nets (distributed to prevent malaria) on goats. Water-carrying donkeys drop dead. Hospital generators break down. Much-anticipated markets for banana flour and pineapple never materialize. And, because there is no market or local storage facilities, a bumper crop of maize—thanks to fertilizer and high-yield seeds—goes to the rats.

In any other case, these small failings might be chalked up as lessons learned; expected setbacks and complications in trying to improve lives in hard and barely developed places. But for Sachs, who arrived in Africa with millions of dollars, a rolodex to the rich and powerful, and little regard for the efforts of the aid community that came before him, readers are left with the sense that these unimpressive results are more than disappointing. They’re a deserved comeuppance.

Munk, a contributing editor at Vanity Fair and former Fortune writer, stretched a six-month magazine assignment into this six-year book project. She never tells readers exactly how she feels about Sachs until the second to last paragraph of the book. She doesn’t have to. Her reporting yields a rich parable of one man’s hubris. Sachs is a fascinating figure who has achieved audacious things before—like convincing leaders of Bolivia, Poland and Russia to administer “shock therapy” to their economies while in his thirties—but Munk makes clear his promise to pull a dozen African villages out of poverty in just five years (a model he plans to scale across the continent) is beyond even his considerable skill and intellect.

A fine writer with a gift for deploying spare, vivid detail, Munk overcomes the burden of what could be duller-than-dirt subject matter—the politics of foreign aid; the ins and outs of Uganda’s matoke market; NGO infighting over anti-malaria efforts—into a lively and at times, quite funny book.

Her narrative weaves together scenes from the field—she focuses on two villages— usually chronicling the many travails of MVP staff, and scenes trailing the jet-set Sachs, who rides around Africa in armored, air-conditioned SUVs. The juxtaposition is not subtle but neither is Sachs, who, at one point in the book, while disembarking a flight in Dar es Salaam, shouts down a fellow passenger (a parasitologist)—“These deaths are on your hands!”— for opposing his campaign to distribute mosquito nets. The parasitologist, like other aid workers in the region, had spent recent years developing a private mosquito net industry and didn’t want to undo the work by giving nets out for free.

Though well-intentioned, Sachs comes across as prickly, dismissive, and supremely arrogant. Most damningly, he appears disconnected from the on-the-ground realities of MVP, the efforts of his staff, and particularly the lives he’s trying to improve. By Munk’s telling, Sachs barely spends any time in the villages, but rather blows through the region, being shuttled in those armored SUVS, between high-end hotels and the offices of African leaders. He drops into villages, only long enough to receive a hero’s welcome—a performance, Munk makes clear—from villagers who are keen to keep the money coming. Meanwhile “the great professor”—as one initially smitten staff member calls him—resists external evaluation efforts of MVP, and Munk finds evidence the organization’s reports are leaving out bad news.

While Sachs and his short temper provide the book’s juiciest bits, Munk effectively draws readers into the stories of the earnest, committed, and (like Munk) increasingly disillusioned group of Africans who work as MVP field staff. They have impossible jobs; tasked with managing the on-the-ground situation while keeping up with the constantly changing and increasingly pie-in-the-sky orders that come down from the New York-based MVP headquarters. While one village coordinator is being asked to write multiple drafts of a business plan for small-scale milk production, his village is facing famine and a drought so severe that an angry mob beats the driver of a water truck.

Moments like this can leave readers feeling awfully bleak about the state of foreign aid and the prospects of ever overcoming poverty. Munk does a good job conveying the complexities of development work and the system of trade-offs involved in foreign aid.

Yet for all of his faults and MVP’s failures, Munk is a bit hard on Sachs. More than once, she offers examples of progress in the MVP villages —drops in mortality and malaria rates; improved school attendance—yet these notable feats feel overshadowed by the steady drumbeat of small failures. Sachs remains one of a very few fierce, public advocates for addressing global poverty. Munk’s portrait is so stinging, it’s easy to forget that fact. Certainly, as a figurehead who commands considerable attention and resources, Sachs deserves the scrutiny. He also deserves more credit than he gets here—but only slightly more. By the end of her book, even Sachs seems humbled, and admits that while things are better in these few villages, a global solution for poverty still a long way off.