
What the movie lacks in drama it makes up for in dodgy historiography, although Robert Langdon, played by Tom Hanks, is often used to provide a counterargument when the film wanders off into more questionable territory.
The key to the plot, of course, is for the protagonists to discover the tomb of Mary Magdelene, thereby proving a genetic link between Sophie and her great, great... grandad, Jesus. It's not clear to me, from the film, why Langdon chooses not to reveal the location of her grave - but there you go...

I find myself wondering about this concern for the descendants of Jesus, in these movies, both Sophie and Bethany are referred to as "the Princess" and great things are expected of them. On many levels this seems strange. In terms of the humanity of Christ, a genetic link surely means nothing - human is human and Christ is therefore linked to us all. In terms of divinity, a genetic link is equally meaningless, since there is presumably no "God Gene" that can be passed on...
Does this concern have something to do with the very human concept of royalty - hence the "princess" theme. We somehow want to believe that some people have divine right to special status. I'm really not sure why? Do we find it comforting? Or does is confirm our own sense of personal destiny? Do these films imply that fate plays a significant role in our lives?
Not sure what's going on here, but I am intrigued with what these two films might tell us about human beings. I'm also wondering what other theories will pop out of the box. Perhaps someone will produce a film in which a major politician or star turns out to be a descendent of Jesus? Or maybe we all are, in our own way...