If you haven't read The Da Vinci Code, you need to indulge and give yourself the pleasure. Actually, I liked Angels and Demons better; however, the Code is a blazing page turner that is quite entertaining. I finished it very quickly simply because I couldn't put it down.
The Da Vinci Code is set in France for the most part. The theories on which the book are based come from the book, Holy Blood, Holy Grail - a controversial book on the history of Christ and the purported existence of a blood line from Christ that extends into our times. Mary Magdalene is thought to have been the disciple bride of Christ (Jesus not being the celibate Savior that most imagine). The Priori of Scion is the inner ring of the Knights of Templar whose major objective (in the book being reviewed) is to protect the members of the Holy Family.
This book is packed with murder, corruption, conspiracy theory - it's very entertaining. Dan sort of ripped off Holy Blood, Holy Grail, but he created an enthralling work of fiction that has seen massive success. Check it out, you won't be disappointed.