This novel tells the story of a librarian named Michael Hearne, who gradually adopts Don Quixote's attitudes and way of life after participating in an amateur medieval drama production. In the novel, the idealistic Hearne begins to challenge and critique the social institutions, modern bureaucracy, and materialism around him, using the perspective of a medieval knight who values ​​honor and justice. Ironically, in Chesterton's eyes, it is the modern world that has gone mad, while Don Quixote's supposedly old-fashioned perspective seems wise in the face of the absurdities of contemporary society. His chivalrous actions gradually spark a kind of social revolution and a longing for a return to medieval values ​​amidst a mechanized, industrial society. The novel uses predominantly thoughtful dialogue to explore philosophical and social themes, making it a witty satire on modern reality and the pursuit of ideals considered impossible.