We get Zach and Lisette's romance in this story. Oh I was so curious about them since we got hints in the previous books and knew it was inevitable. There was no way these two would not end up together. So despite Seth's decree, Lisette helps Zach become more human than he ever thought possible. Quite a feat for an Immortal Guardian. :) I love Zach's transformation from stoic to romantic.
While you probably can read this series out of order for the character's romances, I think that the series is best read in order. That way you get some of the nuances of the characters and the full story arc that has been going through this series. Oh and we get a new character that I can't wait to meet more fully.
Oh I don't want to say too much because I know I would then say too much! I love this series and recommend it highly! I especially think that those that like PNR with some UF thrown in will really enjoy this series and world. I give this book in the series 4 1/2 stars. I can't wait for the next book and eagerly await the next book in the series. I also can't wait for David and Seth's romance! :)