To refresh my memory on the characters and story arc, I reread Ruby Red first (and loved it even more the second time!), then moved on to Sapphire Blue. I liked that this book picked up right where the first one left off so that I could see the emotional aftermath of everything that happened in the last chapters of Ruby Red (There were big developments on both the familial and romantic fronts for the heroine!) There's a lot packed into this book - several eventful trips into the past for Gwen and her partner in time travel, the charming and enigmatic Gideon (SWOON), and some more revelations about Gwen's family as well as the unraveling of some of the mysteries surrounding the secretive organization that has governed the twelve "jewels" who've been able to time-travel throughout history. Gwen's not sure who to trust as everyone seems to leave her out of the loop or tell her stories that contradict what someone else has said. I could understand her confusion, because I changed my mind about who I thought the double agent working for the dastardly Count Saint Germain was several times! There are many shades of gray with the characters in this book as good people do bad things for what they think are the right reasons while bad people seem to have good intentions at times.I loved the addition of Xemerius, the gargoyle inhabited by a dead demon only Gwen could see. His running commentary about what happens to Gwen and the different people she encounters was hilarious. And I think Xemerius was a very clever plot device as he was able to act as Gwen's spy and go behind closed doors to collect information for her. Lesley continues to be the best friend a girl could ever ask for, assisting Gwen with research and giving her a shoulder to cry on when she needed it.I will be very interested to see how everything is wrapped up and what the answer to the biggest question of all "What happens when blood samples from all twelve jewels have been collected and inserted in the chronometer?" Will the secret to immortality be revealed, which is the belief Saint Germain and his cohorts have been operating under, or is the big secret something altogether different?This series has been such a fun read, filled with romance, adventure, and all sorts of puzzles. I recommend it to readers of all ages!