The lives of strangers converge around a mystery unfolding high in the Colorado mountains—and the balance of the world begins to tilt...

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...