Everneath. I read the 2nd book as part of my September is for Sequels Challenge back in 2013. I had won an e-book copy of it, and you can read my review of it here: Everbound. Now, of course since this is a review of the final book in the trilogy, there will be spoilers for the first two books for sure. So you might want to stop reading now if you haven't started reading either of them yet. I feel like this was for sure a good way to end a trilogy. For the most part I was very happy with it.
In the last book, Nikki was able to rescue her boyfriend Jack. Unfortunately Cole wasn't being quite as helpful as he'd seemed. Or he was, but he'd done it for his own selfish reasons, he wanted to take over the Underworld by making Nikki his queen. During the rescue mission he forced Nikki to feed off of him enough that she became the same as him, an Everliving. And while she is now home with Jack and trying to get back to being a normal high school girl, she starts having issues. She knows she needs to feed off of a soul now, but even though Jack offers to let her feed off of him, it doesn't seem to work. They can't find Cole, even though they know he has Nikki's heart. But when they try to steal her heart back from his apartment, all of a sudden, Cole shows back up. He is in Nikki's summer class, but looks different to everyone, except her, she still knows it is him. He tells her that she will slowly need to feed more and more, and can only feed on the person who has her heart, which is Cole. And eventually the only way she will be able to stay alive is to go do the 100 year feed in the Everneath. But things go wrong for Cole, and when the Everneath goes into a fighting mode, the Queen not giving up easily, Nikki and Jack will need to go down and fight. To save Nikki's soul, as well as to try to destroy the Everneath if they can. In a way they get Cole to help them, with or without his knowledge of their true plans.
The ending is happy for the most part. Of course there are some losses, and not everything goes as planned. But it is good to see that love can win, and to find that while Jack does love her, Cole really has as well. A good conclusion to a good series. And now I'm eager to read what the author has coming out next!