Michael Walker in the book She Is Not Invisible written by Marcus Sedgwick. Michael Walker is a supporting character, who encounters the Peak children for less than two hours in total over the course of the book; yet is incredibly pivotal for plot advancement. Mr. Michael Walker serves as an instigator for the plot, a vehicle to reinforce the theme, and as a powerful point of discussion about issues outside of She Is Not Invisible. She Is Not Invisible takes place over a few