Although The Invisible Kingdom does not have characters in the way a work of fiction might, Meghan O’Rourke nonetheless features herself as the protagonist in her own life struggle and occupies multiple roles in the structure of the plot, for she is both the subject of her story and its omniscient narrator. As a result of the nature of her experience, O’Rourke’s role as narrator is also that of researcher and detective. Early in the text, she describes herself as a “co-author” to her illness, which the narrative reveals by recounting the ways in which the state of her body dictates the role she embodies at a given time. Sometimes, O’Rourke is the authoritative, clear-eyed writer who is piecing together complex research. At other times, she leans on anecdote and metaphorical writing to give readers access to her personal experience of being ill. When O’Rourke is at her worst, she describes losing a sense of self in such a way she cannot even fulfill her role as writer, and in these moments, the varying roles of her character collide and are dictated by illness itself.