内容简介：
What if another world exists beneath the ground, housing an ancient secret that leaves the fate of the world as we know it in the hands of six teenagers? Thirteen-year-old Emma Edwards expects her summer with her Uncle Greg, Aunt Debbie, and cousin Alec to be fairly laid-back compared to life with her uptight parents. Soon after she arrives, however, she overhears a family secret: Emma has a special skill unlike anyone else. And she's about to embark on the adventure of a lifetime. Thirty thousand years earlier, a great war broke out, and the spirits of the Kings, the most feared sorcerers ever to roam the earth, were trapped in a single glass sphere. Now, the ancient magic that sealed the sphere is about to disappear, and it's up to Emma and five other teenagers to reseal it. If they fail, the Kings will be free to cause chaos on earth once more. The only one of the group who has never shown signs of magic skill, Emma sets off with her companions on the most important-and possibly the last-journey of her life. But when things don't go as planned, Emma finds herself bearing the greatest responsibility yet.