Every time it seems that Akiva and Karou are finally going to get what they want - a simple life together - the world(s) spin(s) out of control again. They struggle with finding the motivation to keep going when the challenges they face grow ever more serious. Akiva faces the future with and without Karou and has to learn what she wants OF him and what she wants FOR him before they can have any hope at any semblance of a future together.
The other thing that Taylor manages so masterfully is interweaving incredibly complex plot threads so they become relatively easy for the reader to follow. This is world-building and plot development at its best. She juggles a set of worlds and a huge cast of characters each with their own foibles and goals and does so with great aplomb. I read a lot of fantasy and often get lost in the plot - literally - but never with Taylor's work. She also occasionally tells aspects of a scene from different characters' perspectives so the reader obtains a great depth of understanding of the fulness of the world and the story.
It's hard to go into more detail without giving away important plot twists. But I continue to love Mik and Zuse and my heart always breaks for the noble and innocent Ziri who gives of his all to save a world gone mad. There is a lengthy epilogue in this book that rounds out the story nicely, but suggests there are more adventures in store for the characters, even though this is the end of the trilogy. I'd be happy if Taylor left it here, but if she wanted to write more short stories and set them in the future of this universe of characters and problems I'd definitely pick them up and read them.
Brava, Laini Taylor, for bringing this series to a magnificent conclusion.