This is a sort of a detective story in which some book editors become involved in the underground world of cults, especially cults that involve Templars, the Holy Grail, and various related matters. As The Name of the Rose involved signs because it was written at the same time as Eco's Theory of Semiotics, this novel was written while he was writing The Limits of Interpretation, so it is about interpretation and misinterpretation. This is a much better read that The Name of the Rose; the ferretting out of information is great; and the characters are pretty darned good. I believe that Eco modelled Belbo on himself, but that is uncertain, because I have never met Eco.