In an isolated stretch of eastern Kentucky, on a hilltop known as Blade Ridge, stands a lighthouse that illuminates nothing but the surrounding woods. For years the lighthouse has been considered no more than an eccentric local landmark—until its builder is found dead at the top of the light, and his belongings reveal a troubling local history.
For deputy sheriff Kevin Kimble, the lighthouse-keeper's death is disturbing and personal. Years ago, Kimble was shot while on duty. Somehow the death suggests a connection between the lighthouse and the most terrifying moment of his life.
Audrey Clark is in the midst of moving her large-cat sanctuary onto land adjacent to the lighthouse. Sixty-seven tigers, lions, leopards, and one legendary black panther are about to have a new home there. Her husband, the sanctuary's founder, died scouting the new property, and Audrey is determined to see his vision through.
As strange occurrences multiply at the Ridge, the animals grow ever more restless, and Kimble and Audrey try to understand what evil forces are moving through this ancient landscape—just past the divide between dark and light.