This series just seemed to lose quality as it continued. Poison Study was excellent. Magic study was okay bordering on good. Fire Study was just bad. And the worst bit is that the ending of the book, those last few pages, were actually really good... Now if only the whole book could have been written in that vein! 
 Yelena became a really unlikeable character in this book. This coupled with the fact that a lot of the book was a rehashing of events from the previous books and pointless travelling (that only seemed to be there to fill a page quota) made Fire Study rather a taxing read. I desperately wanted to like it but I just couldn't bring myself to do so. On top of that, for fantasy, the author's language becomes far too modern-day, modern-society colloquial and I just couldn't buy it. 
 Very disappointed.