The last chapter in the book The Man Who Was Poe is important because it proves definitively the extent to which the man is detached from reality. Although there have been a number of indications that this is so throughout the narrative, the last chapter confirms that Poe is indeed more interested in his story than saving Edmund's sister. Also, although Poe had previously marveled at the eerie parallels between his own life and that of Edmund's, the fact that, in the Prologue to his work as presented in the last chapter, he crosses out the name Edgar, his own name, and inserts the name Edmund instead, illustrates the extent to which he identifies with the young boy. The substitution suggests that Poe's mental instability is so severe that he cannot distinguish the boundaries between Edmund's existence and his own.
The last chapter in the book is entitled "The Beginning of the Story." This title can be interpreted in two ways. The story referred to might be Poe's own, the one which he has been so anxious to create and which Edmund has, literally and figuratively, destroyed. The title, and the chapter, also contribute to the structure of the book itself, explaining with finality the truth of Poe's state of mind, a fact which enables the reader to understand clearly now everything that has gone on in the course of the narrative. The final chapter brings the story to a full circle; with the last chapter, the reader is carried back to the beginning, and given the key to the mysteries which have been so intricately unraveled throughout the story's course.