(As extracted from my Amazon review of the Italian original text Il Cimitero Di Praga
The story tells of a crook with obscure intentions who, according to the author himself, is going to become the "most cynical and nasty character of all Literature".
In order to serve statesmen, secret services, ministers and police, this enigmatic figure travels around Europe among conspiracies, political intrigues and revolutions.
So, there's no lack of ingredients on Eco's part when narrating this enticing story, built like a 19th century feuilleton, mixing the depths of a classic novel with the elaborate plots of a chilling thriller, the lot enriched with disquieting illustrations (we shouldn't forget that Eco is an emeritus professor of Semiotics - cf. inter alia, his A Theory of Semiotics
One important point: bar the main character, all other interpreters of this novel are real and have done what they have done. Moreover, even the main character does things that have actually occurred, except that he does them in excess and that they probably have been done by diverse people.
Eco's magic, however, makes it so that, between secret agents, corrupt police, traitors, felon officers and sinful clerics, the only invented character of his book ultimately appears to be the most real of them all.
Eco brilliantly succeeds in painting a suggestive picture d'époque, emotionally involving us in a rich narrative full of surprises and in an exhilarating language that only a semiologist like him could produce. Precisely because of this, be warned: as for all of Eco's books, this too is not an easy read, and has a few psychological complexities... Not all you see on the page is actually there!