Fiction by Ian Caldwell.
Ian Caldwell coauthored the book Rule of Four, which I read years ago but still remember as a very good puzzle-type mystery. This book has a similar easy-reading voice but slower plotting and slightly less interesting characterizations, which tells me that Mr. Caldwell probably did most of the actual writing on that previous venture while his partner likely came up with more of the story. At least that's what I think. I could be wrong. Not that it makes any difference, of course; I'm just always interested in the mechanics of coauthor partnerships for some reason.
But I digress.
This book reminded me of The Da Vinci Code, which the book jacket instructs us specifically NOT to compare it to. It's a pretty good intellectual thriller, not action-packed but still with an intersting mystery. I didn't like the ending, though.