I'd give this book 3 and a half stars. I really enjoyed it and became quite gripped at finding out what had actually happened. There was a few ways the ending could go, and it was an interesting one that the author picked that added a bit of an extra dimension. It was somewhat predictable when you think about the characters that you're introduced to in the book though.
Having said that, it was still a really good book and I look forward to reading the next from this author.