Hmm. The Cross book, Pope Joan, is a novel. Last I heard about the subject, Pope Joan was a legend. Lawrence Durrell also penned a novella yclept The Curious History of Pope Joan. As for the thumb thang, since when has reason had any power over word-lovers. YCLIU has about as much force as RTFM. I do like the Canuckian Ffolklorist's name, though. It's an old English one and pronoucned Hyrck.

Ceci n'est pas un seing.