The Seven Keys have been collected, and the world created solely to entertain has come alive. The one who gains control over them will rule Sphere. Who will it be—the Demon King, the digitized players, the corporations, or the people hiding under the masks of the Seven Brothers? The stakes are higher than ever, and the merchant's life is once again at risk—after all, he holds one of the Keys that grant the power to create and destroy worlds at will. Together with Weldy, who has become a Lord of Libros in her own right, Cat will have to brave the most dangerous place in all of Sphere—the Cloud of Bones. His smarts, his cunning, his luck, and the Law of Balance are on his side. And behind him is the might of the Starlight Fleet.