On the east edge of the Land of Oz, in the Munchkin Country, is a big, tall hill called Mount Munch. One one side, the bottom of this hill just touches the Deadly Sandy Desert that separates the Fairyland of Oz from all the rest of the world, but on the other side, the hill touches the beautiful, fertile Country of the Munchkins.

The Munchkin folks, however, merely stand off and look at Mount Munch and know very little about it; for, about a third of the way up, its sides become too steep to climb, and if any people live upon the top of that great towering peak that seems to reach nearly to the skies, the Munchkins are not aware of the fact.

But people DO live there, just the same. The top of Mount Munch is shaped like a saucer, broad and deep, and in the saucer are fields where grains and vegetables grow, and flocks are fed, and brooks flow and trees bear all sorts of things. There are houses scattered here and there, each having its family of Hyups, as the people call themselves. The Hyups seldom go down the mountain, for the same reason that the Munchkins never climb up: the sides are too steep.

In one of the houses lived a wise old Hyup named Bini Aru, who used to be a clever Sorcerer. But Ozma of Oz, who rules everyone in the Land of Oz, had made a decree that no one should practice magic in her dominions except Glinda the Good and the Wizard of Oz, and when Glinda sent this royal command to the Hyups by means of a strong-winged Eagle, old Bini Aru at once stopped performing magical arts. He destroyed many of his magic powders and tools of magic, and afterward honestly obeyed the law. He had never seen Ozma, but he knew she was his Ruler and must be obeyed.

There was only one thing that grieved him. He had discovered a new and secret method of transformations that was unknown to any other Sorcerer. Glinda the Good did not know it, nor did the little Wizard of Oz, nor Dr. Pipt nor old Mombi, nor anyone else who dealt in magic arts. It was Bini Aru's own secret. By its means, it was the simplest thing in the world to transform anyone into beast, bird or fish, or anything else, and back again, once you know how to pronounce the mystical word: "Pyrzqxgl."