This is Michael Slades 13th book, and a complete departure from the other 12 SPECIALX, novels.
If you like locked room mysteries (3), messages in maps, a who dunnit from 2000 years ago, and a pyscho monk from the Congregation for the Doctrine of the Faith,( the new name for the Inquisition), trying to stop the secret from becoming common knowledge, and all this in one book, then this is for you. Yes i can see that you may think this is a rehash or copy from the Da Vinci code. But his is much more than that. This is a story where your brain has to think, and reason. The clues are there.
If you like this book and want to read more, then start with Headhunter, then Ghoul, and work your way up through the series. Each book is very well researched, and the authors that make up Michael Slade bring together over 30 years of trial court experience dealing with the criminally insane. So they should have a rough idea of what goes through peoples minds when committing the acts described in the books. Any research used is listed in the back of the books, to allow you to start your own journey into the mists of time.