I was very sad to hear that series was ending. I remember picking up the first book and thinking what an original concept this was. This book tells the story of Richard and Charlotte (other reviewers have summarized the plot, so I won't rehash). I actually liked Charlotte better than Richard. Not that Richard was a bad hero, but he was a little too Type-A at times. Charlotte was a wonderful heroine though. I liked that she was intelligent and resourceful and generally avoided TSTL moments. Her inner conflict and battle with her magic was well-written. Her sacrifice in the end to save Sophie and any number of others was quite touching.
I would heartily recommend this series to anyone who likes modern or urban fantasy, although you do need to start with the first one not with this book.