A mysterious and compelling literary fantasy that weaves magic, mathematics, love, family—and riddles within riddles—from the author of international sensation The Absolute Book, Elizabeth Knox. Sixteen-year-old Canny Mochrie has always been different; she has a calculating, mathematical mind and she sees something extra. When she begrudgingly joins her stepbrother on a trip to research a 30-year-old coal mine disaster, she meets thealluring Ghislain Zarene, who is held hostage by a powerful spell. Canny starts to untangle the mysteries of the valley—only to find that its secrets are her secrets, too.