In her dreams, Phoebe twirls through rows of sea island cotton as a white dress blows around her knees like a breeze. As she dances, she loses all memory of being born a slave on an Alabama plantation. She lifts up her feet and flies high above the fields, as light as air. Before her a single white star shines.

Thirteen-year-old Phoebe has always dreamed of leaving her life as a slave behind. She has heard whispers about a secret path to freedom, and she has seen what can happen to those who take it and fail. But freedom means more to Phoebe than anything, and when she meets Liney, a strong young woman who picks cotton next to her, they form a plan to escape together.

One night, Poebe, Liney, and Liney's two small children flee under cover of darkness. Following clues from the songs and stories they have heard, the runaways elude slave catchers and reach the first stop on the Underground Railroad. It is only one safe house in a chain that leads all the way north to Canada. But between them and freedom, lie miles and miles of unfriendly country and dangers too horrible to imagine.