The Gnome King of Oz (1927) is the 21st Oz book and the seventh written by Ruth Plumly Thompson. Like 19 of the 20 previous books, it was illustrated by John R. Neill.
In this adventure a new mortal is introduced to the Land of Oz; Peter, a young boy from Philadelphia. At first he teams up with the Gnome King in his escape from exile on Runaway Island. However, when it becomes clear that Ruggedo is not content to be free, but is intent on attacking the Emerald City and gaining control of Oz, Peter resolves to foil this plot. He meets the Patchwork Girl, who has been kidnapped into slavery as the Queen of Patch, and together they journey to the Emerald City. Their quest takes them through strange new lands in Oz and encounters with their unusual inhabitants. Their quest is aided by interesting creatures, like the Oztrich, and the magical powers of Ozites, like Kuma Party and Wumbo the Wonder Worker.