The great Calculor of Libris was forced to watch as Overmayor Zarvora had four of its components lined up against a wall and shot for negligence. Thereafter, its calculations were free from errors, and that was just as well-for only this strangest of calculating machines and its two thousand enslaved components could save the world from a new ice age. And all the while a faint mirrorsun hangs in the night sky, warning of the cold to come. In Sean...