The Magic of Oz is the thirteenth book in L. Frank Baum's Land of Oz series, published a month and a day after his death in 1919. It's subtitle is A Faithful Record of the Remarkable Adventures of Dorothy and Trot and the Wizard of Oz, Together with the Cowardly Lion, the Hungry Tiger, and Cap'n Bill, in Their Successful Search for a Magical and Beautiful Birthday Present for Princess Ozma of Oz.
The story opens with the Hyups, a small community living at the top of Mount Munch in the Munchkin Country. A Hyup named Bini Aru discovered a means of transforming people and objects, by speaking (and correctly pronouncing) the word "Pyrzqxgl". After magic was banned in Oz, he kept this word hidden under a floorboard, where his son, Kiki Aru, eventually discovers it and decides to use it on himself, transforming into a bird and flying out of Oz. In Ev, he meets Ruggedo, the former Nome King, who wishes to use Kiki's magic word to conquer Oz by transforming people into animals.
Meanwhile, Dorothy, the Wizard of Oz, the Cowardly Lion, and the Hungry Tiger journey to Gugu Forest in Gillikin Country, looking for monkeys to train for Ozma's approaching birthday party, where they run into a transformed Kiki and Ruggedo. Also, in another subplot, Trot and Cap'n Bill travel to a magic island to obtain a special flower for Ozma's birthday. The island is dangerous: Trot and the Cap'n are magically rooted to the ground, and begin shrinking away to nothing.
- Ageless Birthday Episode: Like The Road to Oz, Ozma being a fairy is The Ageless and really only celebrates her birthday for the fun of it.
- Amnesiacs are Innocent: The rationale behind erasing the minds of Kiki Aru and Ruggedo with the Fountain of Oblivion.
- Baleful Polymorph: The word "Pyrzqxgl" has the ability to do this once spoken, turning whoever the spell caster directs the spell at into whatever object or beast they desire. However if one is turned into an inanimate object they won't be alive.
- Ban on Magic: Ozma's magic ban was what caused Bini Aru to hide the magic word in the first place.
- Bloodless Carnage: Cap'n Bill impales a kalidah with a stake; this being Oz, the kalidah survives after pushing it all the way through its body.
- Contrived Coincidence: The Wizard and his group just happen to run into Kiki Aru and Ruggedo in the vast forests of Gillikin Country, before they can succeed in starting a rebellion of the animals of Oz against the humans.
- HeelFace Brainwashing: Again this is done to Ruggedo, as well as to Kiki Aru. If Ruth Plumly Thompson's books are taken as canon, it didn't work for long on Ruggedo this time around either.
- Incredible Shrinking Man: After setting foot on the Magic Isle, Trot and Cap'n Bill are stuck with roots growing through their feet, and they gradually start to shrink.
- Magical Incantation: Pyrzqxgl is essentially this.
- Mix-and-Match Critters: The Li-Mon-Eags that Kiki transforms himself and Ruggedo into; Chimera-like creatures with the heads of lions, bodies of monkeys, and wings of eagles.
- No Honor Among Thieves: Both Ruggedo and Kiki Aru plan on using and then betraying one another, because as Baum tells us, this is what wicked people do when in an alliance.
- Small Town Boredom: Kiki has a severe case of this, which drives him to leave Oz.
- Third Line, Some Waiting: Kiki's plot is first and seems like it will be the main plot, then we follow Dorothy's attempt to find a good birthday gift for Ozma, and almost halfway through the book a third plot involving Trot and Cap'n Bill is introduced. They all tie together in the end.
- The Unpronounceable: The word "Pyrzqxgl". Indeed, the only reason Baum gives us this word is because he believes no one will be able to pronounce it correctly; though he cautions those reading the book aloud.