Mister Flint in Oz is a modern Oz book written by Ray Powell. Although first published in 1987, it was originally written in 1969.
Hardas Flint (from Powell's earlier The Raggedys in Oz) learns that his father Steely has been enslaved by Peeramyd, an evil magician. Mr. Flint teams up with the Scarecrow and the Tin Woodman to rescue his father, meeting the wizard Zon and the enchanted bird Quoztal along the way.
The novel makes a few revelations about the history of the Land of Oz that contradict previous stories. It is claimed that Oz was named after Ozma's grandfather Boz and that the kings preceding him were Neillian, Snoward, Plumthon, Cosgrolla, McGrawignera, and Gruellan; Dorothy and the Wizard in Oz says that all previous rulers were named Oz or Ozma. It is also claimed that when the Wizard came to Oz, he used magic he obtained from Mombi to enchant King Pastoria's wife (and Ozma's mother) Ozette, who was then given over to Peeramyd by the witch; The Lost King of Oz says that Pastoria was enchanted before the Wizard arrived.