Library of Souls by Ransom Riggs!
I read the first two books in the trilogy of Miss Peregrine's peculiar children last year, and I was SO EXCITED to read the third. So the first time it got to my turn through my library's online borrowing, I was in Florida visiting my parents. And I accidentally checked it out to my MOM's kindle account. Whoops. I did not have time to read it on her device while we were there, so I just got back on the borrowing list.
A few months went by, and I got another turn! But I was so busy right then (I don't even remember why), I never even got so far as to put it on my kindle.
The third time was indeed a charm, and I finally got to read it, more than six months after first trying! LOL
I have to say, it was worth the wait. I'd grown attached to the children in the first two books, and was really happy to find out how it all ended. Well, mostly happy. Of course it couldn't have a happy ending for everyone.
It's hard to say much about this book without giving away spoilers for it, or for one of the first two books (Miss Peregrine's Home for Peculiar Children, and Hollow City). They are sort of an alternative universe/sci-fi sort of story, but if you're open to that sort of book, they are really great. I'm also excited to see the movie made from the first book in the trilogy.
The ending of Library of Souls, though, was almost too perfect. But I do love a happy ending, so I certainly can't recommend against it based on that.
Oh, while this book could have fit in several categories of the PopSugar reading challenge, I am listing it as the eighth category, a book set in Europe. I'm pretty sure that's where most of it takes place (but of course an alternative part of Europe...).