Rinkitink in Oz [The Wizard of Oz series #10]

"Rinkitink in Oz" is the tenth book in the Land of Oz series. Most of the action takes place on three islands - Pingaree, Regos, and Coregos - and within the Nome King's caverns. Since the original ruler of the nomes, Roquat - who later renamed himself Ruggedo, was deposed in 1914's "Tik-Tok of Oz", Baum had to cleverly rework the tale to accommodate his successor, the well-intentioned - but politically motivated - Kaliko.