Chapter 3 shifts attention to the evil Mimics in their lair in Mount Illuso. The Mimics habitually shift "from one loathsome shape to another" — an ape body with a head of an alligator, and a serpent with black butterfly wings, and a toad with a hyena's head are a few of their choices. Their rulers, King Umb and Queen Ra (a play on "umbra"), reveal their plan to counter Lurline's controlling magic and attack Oz. The shape-shifting royals and their minions fly to Oz as big black birds, and waylay Dorothy and the Wizard of Oz. By stepping into their shadows, Ra and Umb take the shapes of Dorothy and the Wizard; the originals are paralyzed by the magic, and are carried off to Mount Illuso by Mimics. Ra and Umb, in their stolen forms, search Ozma's library for the antidote to Lurline's magic spell.
