Synopsis:

Twelve-year-old Jack Sawyer embarks on an epic quest-a walk from the seacoast of New Hampshire to the California coast-to find the talisman that will save his dying mother's life. Jack's journey takes him into the Territories, a parallel medieval universe, where most people from his own universe have analogs called "twinners." The queen of the Territories, Jack's mother's twinner, is also dying.

Notes:

Co-written with Peter Straub