A Genealogist in Providence is a book cataloged with 999.99 and discovered to be the next-to-the-last book in the Duston Heights Library by Johnny and Fergie (The Bell, the Book, and the Spellbinder; 8).
According to the Dewey Decimal Classification schedule this numbering is reserved for extraterrestrial worlds. Since when is Providence or genealogy deemed extraterrestrial?
Strickland revealed this to be a joke: "Providence, Rhode Island is the home town of H.P. Lovecraft. I was thinking that a genealogist would happen across evidence of alien life forms intermarrying with humans."