The second book of the Southern Reach trilogy! Go read the first one.
This one is much less traditionally horror. (Though the moments it has are quite effective. I particularly hope someone makes a short movie out of the first expedition snippets.) When I began reading it, I was wondering if it’d actually make more sense to read this one first, since there’s a lot about the character trying to figure out what happened in the previous book so you already know and it’s harder to be anxious about. As things went on, though, that dramatic irony expanded to include that precious horror staple, the slow disaster that the main character is unaware of.
Also, after Dresden, it’s just so nice to have a main character who is a nice, pleasant person.