I wasn't sure how I was going to like the Glass Series diverging from The Study set, and though I liked Opal in her short appearances in the Yelena books, I didn't know if her character or the glass-blowing could really carry a book. I didn't need to worry, though, cause Snyder is an engaging writer, and though she has some habits that bug me (a ton of sentence fragments, stretched-thin analogies that she sometimes beats you over the head with), she handled the change-over nicely. Characters from the previous books do make appearances, but the new characters she's created or expanded stand on their own. There were times when I felt she had split her focus a bit, and even though I knew it would all come together (cause that's just what she does), I wanted it a little more tight. I also didn't love the ending, and though I know there will be a sequel that will expand on it, I would have liked a bit more resolution for certain plot lines.All in all, though, deifinitely engaging and fun, and a worthwhile read for Snyder fans.