An amazing book! Not what I was expecting when I bought it, I don't even know what I thought it could be. You'll never know what's next and it really keeps you reading till the end. Finished it in just one weekend. The fact that you don't know much about the four characters (only their professions, not even their names) makes you concentrate completely in the mystery of the Area where really weird things happen. Even scary at some point, but addictive. Total recommendation for those who love psychological thrillers. 
 I haven't had the opportunity to read the second one yet, but this first one leaves a high standard.