Once Upon a Wardrobe is a novel about storytelling. In her “Note from the Author,” Callahan states that she is “fascinated by the ways in which Narnia transforms us” (277). Her book focuses on the capacity of C. S. Lewis’s The Lion, the Witch and the Wardrobe to change its readers, regardless of age. By embedding nested narratives into her novel’s structure, the author also explores the wider impact of storytelling on readers and listeners.

The most notable impact of The Lion, the Witch and the Wardrobe is the story’s ability to ignite the imagination. Callahan illustrates how reading about the magical land of Narnia serves as a gateway to another world for George. The book allows him to escape the restrictions of his failing health and immerse himself in a fantastical universe filled with talking animals, mythical creatures, and epic battles between good and evil. This imaginative experience also serves as a temporary reprieve from his prognosis and his family’s grief. The novel highlights that for George, this escapism is not merely a passive activity; it energizes and revitalizes him.

The introduction of Lewis’s biographical accounts demonstrates that nonfictional tales can also have a transformative impact on others.