Ozzington Noble's wife, Ambrosia, died during childbirth, leaving Oz an only son, Isis. When Isis is stung by a deadly arachnid wasp, Oz must heal him, but there is no known cure and everyone who is stung dies. Haunted by Isis' purple, poisoned face, Oz risks his life venturing into the swamp where Zeldaâa witch and perhaps the only being who knows of a cureâdwells. Zelda predicts Oz has one day to save his son and sends him on a journey across a land crawling with poisonous snakes, carnivorous trees and beasts that lurk in darkness, in search of the last existing hourglass tree, the only hope of saving Isis's life.