At the start of the story, Bungle the Glass Cat has tripped over an emerald in Ozma's palace and broken herself in two pieces. Ozma is absent, visiting Queen Zixi in Ix; Dorothy, the Scarecrow, and the Tin Woodman decide to carry Bungle to Glinda for repairs. On their way to her palace, they stumble into a remote corner of the Quadling Country that is occupied by strange beings made of bricks.
These men of brick, called Brickbats, are not very bright, and through a chain of misunderstandings they decide that Bungle is their promised queen; they keep the others, and Polychrome the rainbow's daughter (whom they had previously captured) as their queen's servants. Bungle is enduring intense distress and humiliation in her damaged state; but she surmounts her self-pity and wounded vanity to rescue her friends and help them escape. Glinda repairs the Cat successfully — and Dorothy notices a change in her: the ruby heart in her clear glass chest now beats, like a normal living heart.