In a dangerous dry season, park ranger Anna Pigeon is posted to Georgia's Cumberland Island on 21-day fire detail. When a plane crashes nearby, Anna and her crew arrive in time to put out the flames, but too late to save the pilot and his passenger, Cumberland's only full-time law enforcement ranger. And when the cause of the "accident" is proven to be sabotage, Anna embarks upon an investigation that threatens to expose dark, clandestine crimes both old and new, making Anna suddenly the most endangered creature on the island.