[3] Meanwhile, Ruggedo the Gnome King (Thompson "corrected" Baum's spelling of "Nome") finds Glegg's Box of Mixed Magic while tunnelling under the Emerald City.

He experiments with the magical items inside the box; after he brings a wooden doll, Peg Amy, to life, and makes Wag the rabbit[4] the size of a man, Ruggedo turns himself into a giant.

After many adventures in the strange lands of Rith Metic, the Illumi Nation, and the Soup Sea, Pompadore and Kabumpo arrive in the Emerald City to find Ozma missing.

The Charlotte Observer declared, "It is a case of 'The king is dead, long live the queen," for Kabumpo proves beyond any question that Miss Thompson will carry on the fame of Oz created by Frank Baum, and such a fact will become a cause of rejoicing wherever good children are to be found.

"[5] The Minneapolis Star Tribune agreed, "There is throughout Kabumpo in Oz a wonderful quality of imagination, a drama of high adventure that leaves not a single dull moment, combined with a charming sense of humor slightly tinged with satire that brings it into the class of master fairy books.