L. Frank Baum 
Oz, the Complete Collection, Volume 2 
Dorothy and the Wizard in Oz; The Road to Oz; The Emerald City of Oz

Delve deeper into the world of Oz in this collection of books four through six in L. Frank Baums classic American fairy tale series.The fourth, fifth, and sixth titles of the iconic Oz series, now in one collection! In Dorothy and the Wizard in Oz, Dorothy and the Wizard visit the center of the Earth, where people are vegetables, glass houses grow, and Oz characters reappear. Eventually they return to the Emerald Citybut will they stay? In The Road to Oz, Dorothy sets out on another adventure with some new friends like the Shaggy Man, Button-Bright, and Polychrome, and some old ones like the Scarecrow and the Tin Woodman. Will they reach the Emerald City in time for Ozmas birthday? In The Emerald City of Oz, Dorothy, her Uncle Henry, and Aunt Em are going to live in the Emerald City. They set out of explore the land of Oz with the help of Dorothys friends, but must rush home again when they discover that the Nome King is busy gathering an army for an invasion of Oz. Will they be able to stop the invasion?