Who is Shane McFarland/Brandy Alexander from Invisible Monsters and what is their importance?

Shannon McFarland is the narrator of the novel, but the reader does not learn her name until the final chapter of the book. The novel begins with Shannon at the bizarre scene of a house fire and a shooting. As Shannon consoles the shooting victim, she promises to tell the woman's story. To do this, Shannon begins with her own story. Shannon is the victim of a shooting herself. Shannon, who was once a model, has lost her lower jaw due to a shooting that took place while she was driving. Shannon manages to keep her calm and drive herself to the emergency room where she discovers kindness still exists when the other patients in the emergency room allow her to go in front of them.