By far, the best in the series thus far. Just when I think Ms. Maas couldn't create something more vivid and breathtakingly beautiful, she delivers and astonishes. I spent a few nights silently struggling to keep my heavy lids open just a while longer and hours that have gone by without having been aware of the time passing. I have updated many times throughout "Heir Of Fire" so I am unsure what to reveal. We see a new part of Celeana in this book, a raw, vulnerable, insecure and very authentically mortal Celeana Sardothien. We meet new characters. 
 Rowan, as frighteningly serious as he is handsome, a fae warrior that inadvertently becomes a dear and true friend that trains Celeana until she is deemed worthy of meeting another new character. 
 Power Hungry and more cruel then kind,her Aunt Mauve. The Fae Queen of Dornelle. 
 Aedion, is the fearsome and charismatic general of the north in the kings army, yet he is also the long lost cousin of "Celeana's".. Who is actually ......*spoiler* The Heir to the throne of Terrasen, the long lost and presumed dead Aelin Ashryver Galathynius!!! 
 My personal favorite new character in Manon Blackbeak of the Blackbeak With clan, she fights anlongside her wyvern Abraxos in the war games orchestrated by the king of Ardalan, to reclaim the Witch kingdom "The Wastes". She is born and breed to know and live by three concepts... Obediance. Disipline. Brutality. As is all of the Blackbeack clan, but Manon is different. Her vehemence and strenghth of character is what makes her disparate in the clan, and part of the reason she is the Heir and the Highest ranking witch. 
 So many Questions and mysteries from the previous two novels are solved yet more questions have arisen. I am very excited to get my hands on a copy of "Queen of Shadows" If the pattern that Sarah J. Maas has begun continues I will be in high fantasy literature heaven.