The Lost Princess of Oz

Book 10 of L. Frank Baum’s beloved OZ books. (1916)

Prince Inga of Pingaree and King Rinkitink and their companions have adventures that lead to the land of the Nomes and, eventually, Oz. When all the inhabitants of Pingaree are kidnapped by the mongrel hordes of twin island kingdoms, Prince Inga and his friend King Rinkitink decide to go to the rescue. Baum introduced the boy hero, Prince Inga of Pingaree, to the Oz series to celebrate the birth of his grandson.