In the coming centuries, Earth's population has exploded and covered the planet with endless cities. It is an unwelcoming world for Nadia Stepan, abandoned at age four and left with only a drawing of the Big Dipper and her mother's parting words: "Look to the North Star, and we will always be there." Nadia grows up dreaming of the vacation spot called Lighthouse Island, in a place called the Pacific Northwest where she believes her long-lost parents must be. As her obsession grows, so too, does her determination to find her way there.

In the meantime, this bright and witty orphan finds refuge in neglected books, and the voice of Big Radio that emanates from an abandoned satellite, patiently reading the great classical books of the world.

When an opportunity for escape appears, Nadia strikes out in search of a dream. She faces every contingency with inventiveness and meets a man who changes the course of her life. Together, they head north toward a place of wild beauty that lies far beyond the megalopolis: Lighthouse Island.