Last year, the U.S. Border Patrol detained nearly 450,000 illegal aliens along the Mexican border. The year before, 417 migrants were found dead in the desert or Rio Grande, their journeys circumscribed by harsh conditions. How many of these hundreds of thousands are children traveling solo? Which Way Home tells the story of the children who leave their families in hopes of a better life. Some will make it, some will not. Andres Zea reviews.