As much as I enjoy the Mercy Thompson series as a whole, Frost Burned felt a bit...lacking to me. In the previous book, the supporting cast was almost completely absent, but the story was so rich and full of lore that it kept me interested. In this book, the cast is there, technically, but we don't get to see much of them or hear much from them. I was happy to see more from Tad and see his character take on more life, as well as learn a bit more about Zee. I hope both will appear more frequently, as they are two of the more interesting supporting characters. There is also a cameo from a member of the Marrok's pack that was a pleasant surprise and interesting to see from a different perspective than we see in the Alpha & Omega series. 
 The pacing of the book was strange to me as well. The action that occurs mid-book felt more climactic than the actual climax. After that, everything just felt off. The last half of the book felt more like a wrap-up until the second to last chapter. We also don't meet the Bad Guy until that second to last chapter, although we know there's someone pulling the strings throughout the whole book, so the end felt a bit unsatisfying. I didn't have time to hate the Bad Guy or really develop any kind of feeling at all toward him. It was just some flat character that needed to die. The very end of the book, after the action, was very weird. We get several chunks of about 3-4 paragraphs detailing what happens in the weeks that follow, and then all of a sudden we're back to right after the last fight. It seemed the author wanted to end on a particular scene, but she also wanted all this other information in there, and the flow was just all wrong. I would have rather had the bits of information about the following weeks at the beginning of the next book. 
 On a positive note, we do get to see Mercy grow in her abilities a bit more, which is something I hope continues. I don't want for her to gain ridiculous overpowered super abilities that was one of the downfalls of the Anita Blake series, but I have enjoyed learning more about what she is and what she can do that has built on the previous book.