Before Dorothy returned to Oz with Charlie, Sam gave Dorothy a copy of the book. As the first case investigated in the Men of Letters bunker involved Dorothy, the book has an added significance as an important literature of the Men of Letters. Charlie realized that the book series contained clues on how to deal with The Wicked Witch, left by Baum for his daughter. The clues led James Haggerty to get poppy extract to use against the Witch and Charlie to kill the Witch with the Ruby Slippers.