The world has been a suspiciously quiet and peaceful place in the three years since the calamity in Shadow Canyon. There have been no more Stone Rot events. A new generation of international men and women are rising to prominence in the fields of business, industry, and politics. Finnley McDougall and Hadley Kobayashi are enjoying a normal senior year in high school. The future looks bright.

But when a young man from New Delhi attends an enigmatic and prestigious summer adventure camp in the Outer Hebrides of Scotland, he discovers a terrible secret. The future of humanity is in mortal danger and time is running out.

The only hope for the world is to drag one scruffy rude, bad-tempered little gome away from his solitary retreat to get his advice. Wullie believes that the only way to avert catastrophe will require a journey to a most dangerous period in history to bring something back. The Bog Witch of Calanais has other plans. The fate of the world for both humans and gomes depends on the outcome of that clash of ideas out on a desolate Scottish moor.