A snowstorm, a mysterious man and an adventure story change the lives of three children forever, secret dangers come to life, and the Battle of Pinner High School begins.

Odin's secret agents arrive in Corfu to kill the last Stone Keeper, and Tella the Mac Mar forges a terrible alliance to destroy the Younger and the people of Scotland. Only one man stands in Tella's way - the young shepherd who goes by the name of Dougie of Dunfermline.

As Scotland descends into bloody civil war, the High Table divides and clan fights against clan.