Necronomicon

Lovecraft invented it as fiction. Libraries keep receiving requests. Card catalogs keep growing entries.

The Necronomicon: invented by H.P. Lovecraft in the 1920s as a prop — the forbidden book of the mad Arab Abdul Alhazred — with a fake history so convincing that libraries began receiving requests. Documented: Lovecraft's letters repeatedly admitting the invention; the 1977 'Simon Necronomicon,' a commercial grimoire that has sold in the hundreds of thousands; hoax catalog entries planted in university card files. The map's cleanest specimen of a fiction achieving documentary existence: the book is real now because belief manufactured it.