Now, there are many books. Including The Expected One. I've read the ones listed above, and a few others besides. As fiction, they're not terribly well written. As fictionalized fact - horrible.
Why horrible? Because they stretch the bounds of plausible. Some of the "theory" I can buy.
- It's plausible that Jesus was married
- It's plausible that he fathered a child, in or out of marriage
- It's plausible that Mary Magdalene fled the Middle East and landed in France
- It's plausible that Mary Magdalene had a child, or two or three
- It's plausible that Mary Magdalene preached her version of Jesus' teachings while living in France
- It's plausible that some of those teachings have survived
But that's it, folks.
It is not plausible to me that there are people today who know that they are descended from the Holy Bloodlines. It is not plausible to me that there are secret organizations whose entire raison d'etre is to preserve and protect the "grail children". It is not plausible to me that the Vatican is spending a whole lot of time and effort covering all this up.
If you want to prove it to me, show me the evidence. Don't show me obscure, never before seen (or independently tested for verification) documents or just tell me that they exist: show them to me. Open the information up to scrutiny -- don't, as one author is doing, say "I know this and I have the proof, but I can't show you - you're just going to have to believe that my book is based on Real Information." If you're interweaving the information into the book, don't write "[character] slowly shook her head, trying to take in this incredible information" and then have them swallow it hook, link, sinker and kitchen sink. Show a little incredulity, because that's what the reader's feeling a whole lot of. Trust me on that one.
Because I don't buy it (and I'm not the only one).
So why are these badly written, badly plotted books selling? I don't think it's because we believe them, I think it's because our standards of good writing and good plotting have slipped. Yes, there are gullible people out there, ones who want to believe in Deep Conspiracies. But the rest of us just don't care as long as its escapism. It's just too bad that this is the form that escape is taking.