Every night, while their families are asleep, Alex Carter and his fourth-grade friends travel down the Glass Staircase, into the magical world of Alaysia. There they ride wumperschniffles, play games, and explore the land. But now the scene has changed, and a castle is being built at the foot of the Staircase. The usually quiet, peaceful scene has been replaced with the bustle of builders and their protecting knights. When a strange newcomer turns...