Another thrilling, suspensive and semiotic adventure of Rober Langdon. The theme of the book revolved around the basic question we as a human being always asked "where we come from?" and "where we are going?" Those are the questions to which Dr. Langdon's friend Edmond Kirsch was going to answer but he got assasinated by christian fanatic. Then the adventure begins. Dan Brown used AI technology, ancient symbolism very well as always.