In 1991, when her daughter's rare, hand-carved harp was stolen, Lisby Mayer's familiar world of science and rational thinking turned upside down. After the police failed to turn up any leads, a friend suggested she call a dowser--a man who specialized in finding lost objects. With nothing to lose--and almost as a joke--Dr. Mayer agreed. Within two days, and without leaving his Arkansas home, the dowser located the exact California street coordinates where the harp was found.

Deeply shaken, yet driven to understand what had happened, Mayer began the fourteen-year journey of discovery that...