Rinkitink in Oz.

Rinkitink in Oz (1916) is the tenth volume in L. Frank Baum's Oz series and one of the most structurally unusual entries in the canon — a book with a fascinating bibliographic backstory that distinguishes it from every other title in the sequence. Baum originally wrote the novel in 1905 as an independent fantasy entirely unconnected to the world of Oz; it was only after reader demand and financial pressures persuaded him to revive the Oz series in 1913 that he recast the manuscript with an Oz-related ending and published it as the tenth Oz book, which explains why, uniquely among the series, no character from Oz appears in the novel until its climax, with most of the action taking place on three islands — Pingaree, Regos, and Coregos — and within the Nome King's underground caverns. The story follows young Prince Inga of the pearl-fishing island of Pingaree, who must rescue his parents and his people from ruthless island warriors with the aid of three magic pearls and the unlikely companionship of the jovial, corpulent King Rinkitink — a figure of irrepressible good humor who travels everywhere on the back of Bilbil, a perpetually disagreeable talking goat whose surliness provides a running comic counterpoint to his master's ebullience.