In the stillness of a golden September afternoon, deep in the wilderness of the Rockies, a solitary craftsman, Grady Adams, and his magnificent Irish wolfhound, Merlin, step from shadow into lightand into an encounter with enchantment. That night, through the trees, under the moon, a pair of singular animals will watch Gradys isolated home, waiting to make their approach.A few miles away, Camillia Rivers, a local veterinarian, begins to unravel the threads of a puzzle that will bring to her door all the forces of a government in peril.At a nearby farm, long-estranged identical twins come together to begin a descent into darkness. In Las Vegas, a specialist in chaos theory probes the boundaries of the unknowable. On a Seattle golf course, two men make matter-of-fact arrangements for murder.