Ultimate Book of Spells Cassy, Verne & Gus are three gifted students who go to an enchanted school where they learn about magic and how to use it. One day they receive a strange talking book in the mail. The book says his name is UBOS (Ultimate Book of Spells) and together they must journey to the center of the Earth to stop Zarlak. Zarlak is a powerful wizard who is stealing all of Earth's magic so he can ultimately escape his prison, at the center of the earth, into which he was banished after a great battle.