Wherein is Recorded the Perilous Quest of Prince Inga of Pingaree and King Rinkitink in the Magical Isles that Lie Beyond the Borderland of Oz. Baum was always one for a long sub-tile! This is the tenth book in the series and was published on June 20th, 1916. Most of the novel had been written by Baum over ten years before as a fantasy novel so almost until the end no-one from Oz appears. Most of the action takes place on three islands; Pingaree, Regos, and Coregos and within the Nome King's caverns.