The Emerald City of Oz

The Emerald City of Oz is the sixth of L. Frank Baum's fourteen Oz books. Originally published in 1910, it is the story of Dorothy Gale and her Uncle Henry and Aunt Em coming to live in Oz permanently. While Dorothy, Uncle Henry, and Aunt Em are being given a tour through the Quadling Country, the Nome King is assembling allies for an invasion of Oz. The climax takes place in the Emerald City, and the story ends with Oz being rendered invisible to everyone except those within it.

Baum had intended to cease writing Oz stories with this book, but financial pressures prompted him to write and publish The Patchwork Girl of Oz, with seven other Oz books to follow.