The Priory of Sion is a real organization, a European secret society founded in 1099. In 1975, the Paris National Library discovered a parchment document known as the "Secret Dossier", which included Sir Isaac Newton, Botancelli, Victor Hugo and Leonardo da Vinci Qi and many other figures were members of the Priory of Mount Xion. Opus Dei, as it is known, is a Vatican denomination—a deeply devout Roman Catholic denomination.The sect has attracted much controversy of late due to reports of brainwashing, coercion and a dangerous practice known as "corporal austerity".Opus Dei just completed its national headquarters at 243 Lexington Avenue in New York City at a cost of $47 million.

All descriptions of artwork, architecture, documents, and secret ceremonies in this book are accurate.