(No spoilers for Glass Sword, but some for Red Queen - you've been warned officially) 
 So, I've put off reading this one for a while, seeing as many of my close friends told me that it was inferior to the first by a lot. And I agree. There was a certain lacking in this book in both story and execution, though further examination might help a bit. 
 First of all, the plot. The plot of this one was a lot less clear than the first book, feeling more like a thin string connecting moments than an actual premise for the book. This could be a result of 'Second Book Syndrome' (where the second book in a series, typically a trilogy, serves little purpose other than creating a connection between the aspects of books one and three), which I think this book has. A lot of ideas from Red Queen are built on, but not completely fleshed out, which apparently we need to wait for book three to get the entirety of. 
 There were a lot of new characters introduced in this book, Cameron Cove, The Colonel, the various 'newbloods', but most of their introductions did not flow smoothly. It was very apparent the role which these new characters would fulfill as they were introduced, and a struggle to tell aspects of the character's personality aside from their powers. 
 Mare is back...and taking a darker turn. She'd a lot more violent, both in mind and actions in this one. Honestly, this was one of my favorite parts of the book. Her changes seemed natural, but sometimes she'd think things and I'd be shocked. The line about electrocuting Maven until his 'bones shriek'...wow. Definitely a change from book one. 
 Cal is back too, and while I didn't see any particularly significant growth on his part, his interactions with other characters created what I consider to me the best moments in the book. He's coping with the loss of his family and place in the world, and no one is giving him any slack. Especially Kilorn. 
 But...there was a slight problem with characterization. Maven is also back and decidedly not Maven. The plot twist was well done in book one, we could see the conflict, but how the character ultimately went with his mother. A strong foundation on which to develop a truly terrifying and strong villain. In this book, however, he was a caricature of a villain. As if, in an effort to make him seem 'completely evil' the book decides to make him do things that are not just bad, but sickeningly so. For me, at least, it seemed very overdone. 
 That's not to say I hated the book. Yes, the plot was rambling and the 'too-evil-for-you' antagonist seemed a little much, but there were some really great moments in it, too. The crossing the river scene was really well done. Mare's descent into madness was interesting. Kilorn was far more likable in this than in Red Queen. The narrative does a great job of providing necessary details without overdoing descriptions. 
 I'm going to follow the series, and hope it gets better. There is potential here.