4 stars.I really wish I read/understood German and could just read the untranslated version of Emerald Green (the next book) but unfortunately, I can't. That is how much I want to know what happens with the rest of this series.Sapphire Blue picks up where Ruby Red left off....Gwen is just getting into the whole time travel thing and because this is all new to her, she pretty much lets the Guardians dictate what she can and can't do. There were times that I just wanted her to push back at them and tell them if they weren't going to tell her what the heck was going on, she wasn't going to help them. On top of the time travel stuff, Gwen is struggling with trying to figure out what Gideon is about. There are times when he is standoffish and others where he is kissing her....she is having a hard time figuring it out and she definitely has feelings for him - she just can't keep them all straight. I suppose at 16, that is to be expected but she does spend a fair amount of the book crying, worrying, wondering what Gideon is doing, does he even like her, etc. I found Gideon a bit annoying at times. He was fairly condescending to Gwen at the beginning and it was odd the way he would be kissing Gwen then hanging out with Charlotte in what appeared to more than just friends. The end of the book explained it a bit more for me and I have to say, Gideon has quite an uphill battle ahead of him if he is going to come back in the next book. The overall mystery of the count and whatever Lucy and Paul are up to are still at the heart of this series. I am very curious to find out what the letters say as well as how Gideon reacts to the news Paul has given him. Fall 2013 is currently feeling a long way off and I will be impatiently waiting to find out what happens next.