Ashlee is terrified of birds. Everybody in the Citadel is. In their stories birds are blamed for the Plague that destroyed civilisation and now, over sixty years later, the Sanctuary Guards patrol the reclaimed city and keep it free of birds and other dangers - such as the Outsiders who live free in the wilds, the Egghead scientists who challenge the truth of the stories, and ideas that lie in books and technologies. Without birds to keep them in check, the bugs take over the harden and become immune to the chemical sprays. So Ashlee's Papa, an Elder in the Council, is sent to other ruined cities to search out a solution. During his long absences, Ashlee becomes a slave to her wicked stepfamily, but when a yellowhammer bird comes tapping on her window it leads her to a message of hope from her lost brother, Felix. He has become a legend, a boy who talks to and flies with the birds. Ashlee has to confront her own beliefs and sift through the lies and fairytales to find the truth about herself, the past, and her own father.