Twelve-year-old Spade is a grave thief along with his father and brother. Following their father's audacious plan to rob a grave in the Wyndhail castle cemetery Spade and his brother get caught in a royal trap, and Spade must find the master of the Woegon: a deadly creature that is stalking the castle by night. Along the way, he meets Ember, the queen's niece, and together they race to solve the mystery of the legendary Deepstones and their connection to the Woegon, the queen, a missing king and the mysterious pebble Spade finds in the Wyndhail cemetery.