3.5 stars. Like other reviews have said, this book was a little weaker than the previous two. I have always enjoyed Grant's use of multiple POV, and still did with this book, but this time it felt like it was stalling the plot a bit. I also feel like the ending could have been done a bit better. The plot was interesting overall, but it wasn't resolved as neatly as it could have been. The last chapter was there to spell out for the reader what exactly had just happened...not exactly the neatest ending. The negatives aside, I did enjoy this book and will absolutely be continuing on with the series. There were quite a few loose ends, but I expect that in the middle of a series. It probably also helps that I am reading this at a time where the next two sequels are readily available, lol. The characters here got some much needed development, particularly Mary, Astrid, Sam, and Diana.
