This book has been getting a lot of hype, and maybe that's one of the reasons I only found it to be...mediocre. I have heard it compared to Gone Girl, which is a disservice, as they only really share two things, they are mystery novels and about a missing woman. The main character Rachel is a trying character, I spent a lot of time not feeling sympathy for or liking Rachel. On one level I like that she is not the typical mystery protagonist. She isn't proactive, she's a busybody, she spends a good deal of time inserting herself into the investigation in the least helpful way. But mostly I just wanted to shake her. I spent most of the book hating Anna, and in the end, while I understand how she perceived events, I never felt for her or liked her. I liked Megan best because her life history, while not the focus of the book, was the most interesting. Her history being revealed could have really tied the three narrators together but ultimately (for me) just didn't function that way.
Overall the book didn't blow me out of the water, but I would be interested to read another dark book from Hawkins to see how she can grow.