3,5/5. Intriguing concept and story. A solid and gripping thriller until maybe the last quarters unfortunately. I was so good and even if some reaction or choice by the characters wasn't always believable. I was still very good. But the ending bring lot of non sense in the reason of it all, the who did it, the why, and the general conclusion was far away for the overall quality of the book. It was going straight at a four out of five, but the ending is a low two. I don,t want to give bad rating just because of a bad ending so I round it up to 3,5/5, but it could have been better. Good book, bad ending!