 Dorothy's return was also inspired by Baum's "Dorothy and the Wizard in Oz" in which Dorothy comes back to Oz in a San Franciscan earthquake.Characters from the Oz books such as Tik-Tok, Jack Pumpkinhead, the Nome King, Princess Langwidere, Handy Mandy in Oz and Ojo the Lucky are also referenced throughout, making fleeting cameos.The novel also references songs from the musical, and the 1939 film, albeit somewhat covertly to avoid copyright infringement.