One of the most popular books of 2016, quickly made into a movie in Hollywood. I haven't watched the movie, because I wanted to get through the book first. It is a fun, fast paced, well-written thriller with all you would expect from a proper mystery book. There is a flawed hero, a mysterious disappearance, a bunch of shifty suspects, slow police officers and yeah, it keeps you guessing most of the way through. I thought I had it solved a couple of times but the ending did surprise me anyway.
I would say it is the kind of book you want to be reading over the summer, next to the beach just for the fun of it. It will not teach you anything new, it will not change your perception of the world. It is just a good old fashioned mystery story, written in a fun and engaging way.