valentino deng and his american friend dave eggers spent 4 years writing a book about valentino's childhood nightmare. >> i think we have a fascination for children who have lost everything and have then become separated from their parents, and we know that this happens during war, but this was something so unique, where tens of thousands of children walking more or less alone across a desert, 800 miles. >> together they've told a tale that captivad millio and even became the must-ad book for a psident. now they've begun a new journey, using a shared passion for education to help rebuild a shattered society. here in the u.s., people take theieducatiofor grand, and he can say, "well, i walked 800 miles, uh, through war-raved sudan just to-- to sit --on therass and and learn abcs in the dirt." >> wow, a human can do this? you know? you know, i'm happy, and i laugh about it, and say, "i'm proud to be a part of this society as well." >> [singing in native language] >> this is something you won't often see in the west, crowds of kids excited about going to school. >> [singing in native language]