Harrow uses characters, objects, and events to highlight the power of words and the importance of stewarding them well. She suggests that humankind should care for words and language, and that in the right hands, they have the ability to open Doors to new worlds. In January’s world, her ability to write a sentence and believe its message creates a real Door leading to a physical world outside her own. Through this metaphor, Harrow suggests to the reader that his or her words have power to open Doors to new worlds as well. If one wields words properly and believes in them, a figurative door can open that brings change to the world.

One major example of Harrow’s emphasis on this theme is Yule Ian’s world, the Written. In this world, words have the power to change reality. People use words to declare their identity on their bodies in the form of tattoos, and sew words onto ship’s sails for blessings and safe travels. Growing up in this world, Yule has a deep appreciation for words. He becomes a scholar of languages and stories, which leads to his first discovery of a Door. Later, his love for words and stories spurs him to write The Ten Thousand Doors for January, and the book gives January the courage she needs to escape from Battleboro using words.