This book, being the conclusion of the trilogy, was arguably the most dramatic of the three. Each book had its emotional ups and downs, but there's an added element of urgency and confusion mixed in throughout the third, making it a highly emotional read from start to finish. I'd just finished the book and haven't had the chance to look through interviews or other statements from the author, but I'm very curious to learn how much of the story was planned out in advance, and how much, if any, was made up as she wrote. For such an intricate story, I would assume it had to be mostly the former. Bray was able to balance all of the elements she had set up well, with no one plot point dominating the story, but various themes interwoven throughout, equally sharing the space that had been set up for them to coexist, all coming together in an epic finale.