"Paul Salopek is already a well-traveled journalist — a two-time Pulitzer Prize winner who has spent most of the past two decades roaming across Africa, Asia, the Balkans and Latin America."

"This, apparently, has not sated his wanderlust. So now he's in a dusty village in Ethiopia's Rift Valley, ready to launch a seven-year, 21,000-mile journey on foot that will take him from Africa, across the Middle East and through Asia, over to Alaska and down the Western edge of the Americas until he hits the southern tip of Chile."

"Why?"