Coming from a place of not having particularly loved Everneath, I have to say that Everbound is in many ways a stronger, more nuanced book. The character development is amazing, the plotting is tight, and the action is riveting. I really liked it, and can't wait for more.Nikki's single-minded pursuit of Jack could have easily annoyed me throughout this novel, and at times came very close, but I was surprised at how much I sympathised with her. She feels guilty that Jack sacrificed himself for her, and is determined to do anything to get him back. But I think she made some weird decisions at the beginning, especially going to graduation and not turning to her friends for help. Nikki's always had a unique way of dealing with things, but I didn't really get her until she embarked into the Everneath with Cole.Which is where things got very interesting! I always thought Cole just got in the way of the sweet romance between Jack and Nikki, but Everbound reveals that he is sweet and thoughtful and definitely worthy of love. It's hard to read about Nikki constantly dismissing his feelings for her, because they're so obvious to everyone else. The author has somehow made me believe in this love triangle, and suddenly I'm rooting for Cole - even going as far as dismissing Nikki's feelings for Jack as an attempt to hold on to her unattainable past! I think this is a hallmark of good writing, and I am genuinely conflicted in my hopes for the next book.Although Jack is basically absent throughout this book, I love that Ashton kept him alive through the dreams he shared with Nikki. I also liked the flashback sequences in the later parts of the book, which allowed Nikki to explore the beginnings of their relationship. I think it was all very well done, but like I said, this is definitely Cole's book, and Cole's time to shine.I still think Nikki spends a lot less time with her family than is appropriate - especially in the context of her desperation to come back to the Surface in the first place. Instead of making the most of her time with her father and brother, and perhaps appreciating them more now that Jack is gone, Nikki jumps on every opportunity to abandon them, and doesn't really talk to them in the rare moments when she is at home. It's very disappointing, and I can't help but question how she can possibly love a boy, any boy, more than her father and brother.The best aspect of this book, for me, is the expansion of the mythology. Readers are introduced to the complex layout of the Everneath and its denizens, and are given glimpses into the lives of the immortals that transverse the two worlds. I think it's really cool how well-known Greek mythology ties into the story, and I liked picking out all the references. I liked the mechanisms the author uses to expand the world, such as when Cole impatiently explains things to Nikki, or when Mrs. Jenkins reveals an interesting nugget, but I sometimes felt these scenes bordered on info-dumping.I've come a long way from Everneath, where I hated Cole and didn't understand Nikki! Everbound is an amazing sequel - complex, engaging and heart-wrenching - that builds on the foundation of the first book and sets us up for a thrilling conclusion. Be warned, however, Everbound, like is predecessor, ends with a heart-breaking cliffhanger that will have you desperate for more.A copy of this book was provided by the publisher for review.You can read more of my reviews at Speculating on SpecFic.