The more famous Da Vinci Code is informative about all sorts of hidden parts of history that underwent attempts of being wiped out, and this one is more about a similar recent part of history together with some futuristic science.
If you liked DVC you might like this, by the same writer, and if you are into history or archeology you might like it - I liked it for the information about historical things and the way it was connected to science of today and tomorrow, and too human nature. I like DVC and other two more, but this is very worth reading once.