3.5 stars. 
 I read this aloud to my sons, 15 and 12. It seems the teenager is done with me reading to him, so it is also likely to be the last book I've read to both of them. 
 I asked twice during the course of the reading if we could stop and read something else. I wasn't getting into it, the romance scenes were too gaggy for me (the 12 year old covered his ears during those parts, heh), and I wanted to be done. But both times at least one kid urged me to continue, and I'm glad we did. By about 60% into the book, I accepted I was in it for the long haul, and by the end, I even enjoyed the experience. Not so much the boys, though. Neither of them wanted to continue the series and read the second one after it gets published. Yet they wanted to keep reading. Whatever! 
 The character depiction is strong, and since there are only a handful of them, you do get to know them pretty well. I preferred Kiernan over Trey, but hey, at least the main character had two boys to choose from. 
 My older son felt like the author didn't describe the whole time travel thing well, and based on the number of times it hurt my head trying to unravel what was happening, I tend to agree. Nailing down the specifics of time travel in a novel in a way that makes sense is quite a challenge for any author. The addition of CHRONOS and their rules helped with this, but still, it's no The Time Traveler's Wife. 
 The historical scenes are well done. Walker depicts the bad guys in a believable manner. Even though I found Kate's mooning over the boys too mushy, by the end I was touched by the gestures they made to her. 
 I am guessing plenty of teens (and maybe tweens, if they don't mind romance and some mild violence) will like Timebound. I am glad I read it, but I don't plan on reading the next title in the series.