The best in the series so far, and the first one that has inspired me to run out and get the next one right away. I think each book has generally improved on the one before, with this one surpassing them all to the point that I'd recommend starting with this one. It's completely stand-alone -- none of the characters or events in the previous books matter to the understanding of this one, and nothing in this book will spoil the prequels.
This book begins with an enchanted Scottish Laird -- a druid -- woken from his sleep by an American tourist disillusioned with life and love. Their romance blossoms easily and early, but just when I was beginning to wonder what the rest of the book would be about, the story throws me for a loop. And then again. In terms of romance, this was very well done, and very passionate.
I also enjoyed the fantasy/time travel element very much. Both the magic and the time travel truly mattered to the story and impacted the events...they weren't just tools to put a modern day woman into the arms of a 16th century man. (Although that happened too.)
There are two reasons this book didn't make five stars for me. The first is my general difficulty with time travel romance, particularly in terms of wondering how on earth the characters managed to communicate with one another. This is true of every time travel romance, and I know it going in, so it may be an unfair judgment, but there it is.
The other thing was the whole "cherry picking" nonsense that came close to driving me crazy as the book wore on. At the beginning of the book, Gwen was actively looking for the right man to take her virginity, and started thinking of him as a cherry picker. Crude, but amusing...the *first* time. After a while, it was like, "All right, you were a 25-year-old virgin. I get it. Enough, already!" I also wasn't quite sure I understood why she was a 25-year-old virgin, especially since she seemed so eager to give it up. The whole thing could have been handled much better, IMO.
But other than those nits, I highly recommend this book to anyone who likes fantasy and romance. This is a rare competent blending of both genres.