As immigration debates boil around the world, Theroux set out to explore a country key to understanding our current discourse: Mexico. Just south of the Arizona border, in the desert region of Sonora, he finds a place brimming with vitality, yet visibly marked by both the US Border Patrol looming to the north and mounting discord from within. He spent time communing with people of all stripes who remain south of the border even as their families brave the journey north. In doing so Theroux uncovers the rich, layered world behind today's brutal headlines.