And Vatican has to select a new Pope but Cardinal 4 person abducted to somewhere. And Vatican believed that all that happened about "illuminati"by Assasin. Because after Cadinal disapeared,It has a symbol about illuminati.It is a symbol of illuminati.The symbol of illuminati looked like a symbol of Satan.So vantican send Vatican officials to look for Langdon . And in a ceremony to appoint Pope, four candidates are kidnaped by the iluuminati and he tells there is a boom somewhere in Vatican. Then Langdon helps to find all the candidates and the boom in Vatican. He must know the secret of the four symbols of iluminati in order to help each cadidates in deferences place by each symbols. Unfortunaly, he can help only one. Then he knows the truth that the real villian is not the illuminati but it is Pope's secretary.