It's fair to say I liked this round better because it involved books, libraries and the Bodleian itself. Including whether it's at all possible to break into the Bodleian to swap out a reproduction for an original (ie, doing the right thing) which made my palms sweat (ie, feels very, very much like the wrong thing).
I also enjoyed King's take on Japan, especially the world of Japan when Hirohito was still Crown Prince. King sprinkles small reminders throughout of what US policy towards Japan at the time implied for the upcoming World Wars. As well as providing a lot of cultural information, to explain to a novice why Japan's customs may seem so odd to us Westerners.
The mystery itself was a bit too standard. It was clear who the real "bad guy" was almost right away, and the reveal of where the mystery book was hidden was truly blasé. But things got a little bit more twisty towards the end, also not completely unforeseen, but complex enough to be satisfactory.
Also, I'm nearly caught up! One book to go... until King writes her next one.