On May 25, 2004, the world transformed. Nearly all signs of civilization vanished, leaving in their wake a bizarre landscape of wilderness, advanced technology and magic, and leaving Harrison Cody very much alone. After weeks of surviving in solitude, he hears a voice on the radio, beckoning him to cross a thousand miles of terrifyingly random terrain to meet her, and any other survivors, in Chicago. Eager to find any remnants of humanity, he sets forth, joined by an unexpected—and inhuman—companion.

For Dorothy O’Neill, the end of the world means she will never finish ninth grade. On her own, she builds a home in the ruins of a strip mall, relying on her ingenuity and hard work to maintain some semblance of creature comforts. When another survivor arrives, he brings futuristic technology and stories of monsters he has encountered. Armed with this information, she takes a new interest in exploring her world, but she is not prepared for what awaits her, and the new arrival has brought his own set of problems.

On their separate journeys, Harrison and Dorothy begin to piece together what has happened to their world. Their questions have answers to be found in what remains of Chicago, and from the mysterious voice on the radio offering the hope that civilization can be rebuilt.