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 light ... and into an encounter with enchantment. That night, through the trees, under the moon, a pair of singular animals will watch Grady's 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 all the forces of a government in peril to her door. 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. Along a highway by the sea, a vagrant scarred by the past begins a trek toward his destiny.