I went through this book as quickly as I had the first one, but I do have to admit that I just wasn't as enchanted with Magic Study as I was with Poison Study. I did like seeing Yalena visit her home country & meet her family, plus I did like the character of Opal. (Which is good because otherwise I might not enjoy the Glass series.) 
 Since there's already a ton of reviews, I'll not waste time rehashing the basic plotline of the book. I'll go straight into what disappointed me in the book. 
 My only real complaint with the first book was that at times Yalena was a bit too perfect. She'd always had the right answer, always had someone come in the nick of time & everyone loved her. (Other than the villains of course.) That complaint was my biggest problem with this book. Yalena came very dangerously close to becoming a Mary Sue at times. (Ah heck, who am I kidding. She WAS a Sue in this book!) She always had the best magic, always had the right answers, always was the one to save the day. I enjoyed the book very much, but at times in the book I really just wanted to see her stumble a bit or make a big mistake. The "mistakes" in the book didn't really seem to count, because she always seemed to be in the right eventually. Hopefully the next book will break free of this trend- the whole "greatest thing since sliced bread" heroine runs pretty thin after a while. 
 Overall though, this isn't a bad book. I found enough here to keep myself entertained & go through the book. That whole perfect Yalena thing needs to go, otherwise that really will ruin the series if the author isn't careful. If a character is too perfect, then the character really has no room to grow, not organically anyway.