4.5 stars. 
 I left Glow completely stunned and confused - there I was for the entire book despising Seth, then the entire ship gets flipped on its head and I'm unaware of who I should have been hating all along. Authors who are able to transform your perception of a character within a few sentences are rare; Amy Kathleen Ryan is one of those. This continued on into the sequel, Spark. For a good portion of the book I despised Kieran more and more as the pages flicked by and liked Seth in Spark more than I did Kieran in Glow. Ryan just has a knack for writing fantastic characters no matter their ability to instill love or hate in you. 
 If he ever did get out of here, he'd show her he could be a good person. It didn't matter that he could never have her. He just couldn't stand the thought of her thinking badly of him. And maybe, just maybe, he could help her, too. Because whatever had happened to her on the New Horizon had pulled her downward, bent her back, hollowed out her eyes. If he could see her again, he'd take nothing from her. He wanted nothing. He just wanted to help--be a friend. 
 The above quote from Seth just presents the transformation that occurs in him within the first couple of chapters from his POV... but I must say, it felt like Ryan has two different styles of writing for two groups of characters: those that we are made to side with and like and those that we are meant to dislike and wish would see the light - or just die. This was probably why I liked Seth more than Kieran in Spark, but if that logic is bizarre from your view then it must be something else. Having liked Seth more than Kieran I should have enjoyed Spark more than its predecessor, but that wasn't case; maybe I would have if I reread Glow with a different perception, knowing where book two was going. Both books are equally as good, the first focusing more on religion, the second more on politics - and both involve ceaseless morality dilemmas, which I think in Spark was upped the ante. The morality really showed all sides and complexity of the characters making them dimensional however much I thought there were characters labelled as good or bad for the reader. 
 I go on and on about characters but they are the ones that drive and provide you with the twists and turns in the plot; they are unpredictable in their actions and behaviour. Even new additions to the story are unpredictable and have meaning to what they do/have done. It's best to keep you're emotions locked up because hate can go along way with such a book as this. However I give you permission to harness that hate for the end of the book because it leaves you on a cliffhanger that will have you regretting picking up this book so early from book three. I am eager to see what Ryan is able to do next in book three and I am positive that it will be better than both book one and two.