So far I've adored everything that Melissa Marr has written in the Wicked Lovely series. This book isn't much of an exception, since I like it as well. I just didn't like it as much as I did the first two books in the series. 
 Fragile Eternity finds Seth, Aislinn's mortal lover, in desperate need of a way to live forever. He knows that as a mortal, his years are numbered & that eventually his girlfriend will turn to Keenan. The Summer King is mostly content to wait, since it means that he gets to further romance Donia, the Winter Queen. However, Keenan isn't above a little trickery of his own now & then. Meanwhile Bananach, the fae representation of war starts to stretch her wings in the hopes of a war that will stretch across all of fairy! 
 I did like this book. It's just that this isn't really the same type of book in comparison to the previous two. I think that its partially because this is very much a transitional novel. While both of the previous books were standalone novels that (at the time) didn't interact, this book changes the tone from semi-isolated episodes to something that is faster paced & ties everything from the previous two novels into one conflict. Since it is that kind of novel, I can forgive the shift in tone & pacing. 
 The book is still pretty good. It just seems that at times it took an awfully long time for the story to go someplace. To be honest, this almost felt like it could've been a little bit shorter in places. Ash spends a lot of time moping, feeling sorry for herself & being blind to how much of a jerk Keenan is. (Hey, his treatment of Donia is terrible.) Seth spends a good amount of time being the befuddled mortal. Keenan spends all of his time being a jerk & not thinking of possible consequences. This isn't entirely bad, as there are reasons for Ash & Seth to be the way that they are. But like I said- the book just seems to drag in a few places. 
 If you've liked the previous two books, you will probably like it. If you haven't read the previous two books, go read those first. This isn't a standalone & it draws heavily on the things mentioned in the last two books- the first book especially. I waffled on the rating for this review at first. I liked it more than 3 stars' worth, but not entirely enough to give it 4 stars. In the end, I gave it 4 stars because my liking was closer to 4 than 3.