Dear Dan Brown,
I know, it’s a pretty novel (no pun intended) writing trick: your protagonist is a super-genius in X field, so you can put them in any situation and they can explain everything to the reader (see also: everything written by Warren Ellis). All you have to do is get your character from place to place to explicate the plot and — BONUS! — because the protagonist is reciting your research everyone gets to know how smart you are.
The problem is there are only so many ways to successfully pull that off, even if you do earn some goodwill by making your main character a professor (and therefore used to lecturing). When you get to the point where a character (in the middle of a murder/kidnapping/fatherraping investigation, no less) slows down a Federal investigation by telling them to Google something rather than just spitting out the answer (chapter 21, page 87), you’ve officially run out of ways to hide your one author’s trick.
Me? I overuse the “open letter” shtick. But it’s not the ONLY thing I overuse and write poorly. If you ever get a chance to see over your enormous stacks of money to this blog post, I hope you’ll see that I write this out of love. I love the premises of your novels, it’s just that I wish the craft was more subtle.