This book feels like a good mix between The Secret History and Mexican Gothic. Honestly I really liked it and read it quite quickly, but I do wish it was shorter. There was a bit in the middle where I figured out the "twist" and though I wasn't sure if I was correct, after that it really felt like it was dragging and I just wanted to get on with it already. Reason #1 why I don't love mysteries - even though this leans more gothic horror (even though I think the publisher categorizes this in fantasy?) I hate waiting around for "reveals." I will say though, I don't think my correct guess ruined the surprise, it just made the middle feels like it was lagging. 
CW: high-demand religion, abuse. 
I actually think this would make a really great bookclub book to discuss the themes and allegory throughout. I think it would be really interesting to explore this book through the lens of comparing it to the lifestyles of people participating in high-demand religions; a lot of grooming and manipulation going on.