Everything you need to understand or teach The Lost Years Of Merlin by T. A. Barron.
The Lost Years of Merlin is an adventure quest built on the premise that as a boy, the great wizard Merlin spent several years in an enchanted land. Drawn there by his need to discover his forgotten origins, he finds the countryside dying from a blight and curse. The tree-girl Rhia persuades him to help her reverse it. They go off on an almost-impossible mission to confront the evil being Rhita Gawr and his puppet, King Stangmar, in their shrouded castle. Traveling through many miles and dangers, they meet good, wicked, illusory, and undassifiable beings that help or hinder them along their way. Rhia is kidnapped and taken separately to the castle, and Merlin, in the company of a miniature giant and riding the hawk Trouble, manages to traverse the last barrier, a spooky darkened landscape, and enter the castle.
There, he and Trouble defeat Rhita Gawr&mdash...