Anyone who is doing any kind of serious research into Dan Brown's Da Vinci Code should be aware of some important information that isn't revealed in 'Jesus, Mary, and Da Vinci'. Mr. Brown's book, which he claims, in the preface, is based on 'fact' is actually perpetuating a known and established FRAUD with respect to its claims regarding the 'Priory of Sion' and the 'Dossier Secret' documents in the French National Libary. It has been established beyond reasonable doubt that the 'Priory of Sion' and the 'Dossier Secret' documents are in fact the fraudulent creation of a circle of anti-semitic French nationalists who revolve around the figure of Pierre Plantard. Mr. Plantard was a primary source for the authors of 'Holy Blood, Holy Grail' which Dan Brown attributes as one of his primary sources for the 'Da Vinci Code'. This information has been brought to light in the excellent video 'Breaking the Da Vinci Code' as well as by CBS's 60 minutes, which filmed their own investigation into Mr. Brown's claims on a show that recently aired on April 30th.
Basically, Mr. Brown propagates the same fraudulent information that he inherits from his uncritical use of 'Holy Blood, Holy Grail'. Not very good form for someone who claims his fictional novel is based on 'fact'. There are numerous other errors, misrepresentation, and outright fabrications in Mr. Brown's book that aren't adequately addressed in 'Jesus, Mary, and Da Vinci'. Those who are truly interested in some solid, scholarly research on Mr. Brown's book would be well served by viewing the excellent video 'Breaking Da Vinci's Code' also available on Amazon.com.
There's nothing wrong with reading and understanding the 'Da Vinci Code' as a work of fiction, which it is, but don't confuse this book as a serious representation of history and theology, which it most certainly is not.