Not too bad. I expected something more science-fiction oriented while is only a mystery story. There are some facts that occur not perfectly explained and that doesn't fit very well with what is happening.
Honestly I maybe would have given three stars because this book is able to entertain the reader quite well. But, on the other hand, the final doesn't make sense at all. Seems only that the author tried to lead quickly the story on science-fiction/horror track but without any reason.
Sorry for the language, I attempted to write a review in English :-)