This review was originally posted on Ruby's Reads. 
 Let's recap a little, shall we? In the Sky Chasers universe, two large ships (in my mind, they always resemble the Starship Enterprise) left a dying Earth behind in search of new, habitable planet. En route, the women found that they were unable to have children. Luckily, the ships were stocked with scientists (only the best and brightest were invited on-board) and those on the Empyrean soon found a cure. Mysteriously, however, the cure sterilized the women of the New Horizon. Angry and embittered, the New Horizon attacked the Empyrean, killed most of the adults, and kidnapped the fertile young women in order to harvest their ova. 
 At the end of the first book, Waverly and her contemporaries were unable to save their parents, but did get the girls back to the Empyrean. Waverly reunited with her almost-boyfriend, Kieran, only to discover that, in taking over control of their ship, he'd started to resemble Anne Mather, the wicked witch of the New Horizon. As if everything that had already happened to her was effed up enough already. Oh, and Kieran and Seth had some power struggles aboard the Empyrean. In comparison, their conflict was like a college frat rivalry. #Justsaying. 
 Spark picks up a little while after Glow ended. Waverly and Kieran are estranged and Seth is in the brig. Waverly, broken and defeated from what happened to her on the New Horizon, her failure to free their parents, the fact that she killed someone during the escape, and finding that she can no longer relate to the boy she thought she would marry, is just going through the motions. It doesn't help that half the remaining crew blames her for leaving the parents behind and the other half resents her for not supporting Kieran. At first, Waverly is content to wallow in her misery. Gradually, however, she begins to realize that no one is keeping Kieran in check. Her determination to do so finally reawakens her to her responsibilities. 
 Kieran, by contrast, is struggling to maintain absolute hold over the control of the Empyrean. As the novel goes on, he sinks deeper and deeper into his desire for control. There's definitely an "absolute power corrupts absolutely" mindset to Ryan's development of Kieran's character. Kieran very much believes that God has chosen him to lead the Empyrean-and that means that anyone who doesn't support him is basically a heretic. 
 And Seth? Well, Seth has finally started to figure out that he might have gone too far in book one. He's as much in love with Waverly as ever, but doesn't believe he deserves her. When he is mysteriously freed from the brig during an engine malfunction, Seth decides to try to prove that it was a terrorist who was responsible for the explosion. He's Kieran's foil at every turn, the leader who is more interested in saving his crew than in keeping power to himself. Given the events of book one, this element felt a little forced to me. I'm not sure where Ryan is going with Seth and, frankly, I'm not sure she does either. I want to like him-because I desperately to want to likeone of the characters-but she's not making it easy. 
 Spark is told in alternating narratives by Seth, Kieran and Waverly. I can't make up my mind over whether or not this is an effective technique. On the one hand, this gives us a unique insight into the minds of all three protagonists, and the events on the ship. On the other...unique doesn't necessarily mean "more easily understandable." Or relateable. Just because I knew what Kieran was thinking when he was being an a** doesn't make him any less of one. And that, I think, is the crux of my problem of this series. The characters take turns being unlikeable, which is not balanced by extended periods of awesome. 
 All in all, reading the Sky Chasers books is rather like watching a car crash-I can't look away. On one level, reading it makes me fume and feel impotent. On the other, I can't stop myself. I want to know what happens next. And, I really, really, need Anne Mather to get her comeuppance. Also-and maybe this is because I'm a teacher-I'm fascinated by the idea of a society that's run entirely by children. Spark is a book with problems, but it's also compulsively readable. I recommend it to anyone who wants an active read. You'll be involved and invested despite yourself. It will make you think-and that's not a bad thing. Books that make you want to run to your computer and email your blogger friends must, by definition, be awesome.