Alex Wagner has always been fascinated by stories of exile and migration. Her father's ancestors immigrated to the United States from Ireland and Luxembourg. Her mother fled Rangoon in the 1960s, escaping Burma's military dictatorship. In her professional life, Wagner reported from the Arizona-Mexico border, where agents, drones, cameras, and military hardware guarded the line between two nations. She listened to debates about whether the United States should be a melting pot or a salad bowl. She knew that moving from one land to another-and the accompanying recombination of individual and tribal identities-was the story of America. And she was happy that her own mixed-race ancestry and late twentieth-century education had taught her that identity is mutable and meaningless, a thing we make rather than a thing we are.When a cousin's offhand comment threw a mystery into her personal story-introducing the possibility of an exciting new twist in her already complex family history, Wagner