Into the Drowning Deep is, in a weird way, why I don't read a ton of adult SF/F books. I really enjoyed this book. 4 stars is high. And yet, at the same time, I genuinely feel that if this had been YA, I would have given it 5 stars. One of the main hallmarks of adult SF/F is the expectation of a longer attention span from readers, meaning that authors tend to get more into the nitty-gritty of their worldbuilding or, in this case, their science. While this certainly isn't bad, I think I just generally don't have that attention span, which leads to it taking four weeks (in the case of this book) for me to finish a book -- a quality I find frustrating and which prohibits me from attaching myself to the book of characters in the way I can when I finish a book in a few days or less.

Anyway all this rambling to say: excellent book, mermaids were frightening and perfect, and Seanan Maguire is a god among mortals.