If you read the other books of this series then this one is very predictable but still makes for a good listen. The series as a whole is excellent and Christian Rummel did an awesome job with his narration.
This book certainly tied up the loose ends, and has some very good passages. However the final war encounter was spoiled for me because the "twist" was so obvious for a long time before the normally smart characters worked it out for themselves. I kept shouting "No, you idiots, they are [doing X]". The final dialogue scene to resolve the romance subplot was nicely done, also with some twists.
As I needed something to keep me awake in my car for my 10 hour drive to Canada, this book turned out to be the best solution. It kept me alert and awake for the entire trip, and thus safe, without the risk of dosing off as is the habit of long distance drivers.
This book is highly recommend it for folks who want a thrill as well as those who are piqued by science fiction historical mystery.
I love this series and I think this wrapped things up nicely and leaves the ground work for the next book in the series. Can't wait!