On an isolated isle off the western coast of Scotland, spirited American Jane Wunderly must investigate a secret society where esoteric rituals blur the line between what's real, what's illusion, and what's deadly...
Jane, set on solving the crime and catching the next ferry with Redvers, realizes she may be among the few still grasping reality. One high-ranking member searches for the killer by attempting to access otherworldly planes of existence, while others become immersed in a strange solstice ritual. Then there's Nightingale and the rivals who discarded him to start a new temple. As a second death brings fresh clues into focus, Jane needs to navigate a frightening dilemma-playing along won't help her crack the mystery, but revealing too much could be a fatal mistake.