The Ghost in the Closet began in San Francisco as a live performance about Mabel's best friend, Tom Metz, a technical writer and artist who Mabel insists "is Frank Hardy!" She decided that it would make a great book and enlisted Tom to help her with the research. (Having never read any Hardy Boys mysteries, "all that wrestling stuff" was a mystery to Mabel. She was also amazed at how "phallocentric" the books were—tons of rockets and trains. While the two series have the obligatory gender-related differences—the girls in Nancy Drew chat while the boys rib and wrestle—both series' characters share an obsession with objects.)