This book has a great plot (although cringily predictable at times). I loved how it built and the magical realism in it which I’ve been into lately. I liked the cast of characters, but did not think they were all fully developed and some chapters felt their purpose was just for the reader to see that they arrived at an “a ha” that was already revealed in an earlier chapter from that character’s perspective — i.e. the extra perspective didn’t always add to the story. 
Giving 4 stars because it was a “can’t put it down” novel and the topic of cartography and the setting of the library was great.