Only reason I'm giving this a 4 is because I'll be honest the first 100 pages or so are kind of difficult to get through. It's definitely a slow burn and, especially at the beginning, it's easy to become discouraged: random vocabulary thrown your way, difficult to map locations, endless repetition. That being said, this is probably the greatest reveal and one of the best plot concepts I've ever had the pleasure of discovering. My best advice: read this book, go in blind with no previous knowledge, and be patient for the first bit. More than worth it in the end. Also, I loved the ending.