Whoa! Onyx is even more explosive and steamy than Obsidian, and the stakes are even higher as the DoD has come into town, keeping a close eye on the Luxen, and Katy. The book is full of action and intrigue, a little betrayal and a whole lot of Daemon!I really have to give Katy props for not losing her head every time she was anywhere near Daemon in this book – he’s wonderful when he’s not trying, so you can imagine how devastating he is while trying to convince Katy that he feels something real for her. Katy stands up for herself and remembers that it was only a few months ago that Daemon was being very mean and rude to her, and doesn’t give in easily. Katy and Daemon have both grown a lot in this book and I loved getting to know them better and watching them unlock one another’s secrets.Since Katy is a book blogger, there are a lot of little throw away lines that made me extremely happy while I was reading Onyx. She records an IMM post with Daemon (that scene is wonderful!), mentions Tod from Soul Screamers, and I think, reads Touch and Shattered Souls at different points (the last two are guesses based on how the plot and cover are described).The secondary characters in the book also shine through. As usual Dee is vibrant and dependable, and I enjoy her friendship with Katy. She also got an expanded storyline in Onyx, which I enjoyed. Katy’s other school friends also develop a little more, although I would have enjoyed having them interact more with Katy instead of the usual ‘isn’t Daemon hawt?’ routine. Katy is struggling to deal with the aftermath of Daemon’s healing in Obsidian, and there’s a new character in the book, Blake, who helps her out with that. Daemon is none too happy that there is another guy in Katy’s life, and the ensuing jealousy and snark whenever they are together is simply hilarious.Katy’s strange new powers and the appearance of the DoD bring a lot of action and mystery into her life, and she is quickly thrown in the thick of it. The suspense drives the plot along at break-neck pace and kept me guessing at every turn – every new clue only deepened the mystery further. Katy is prone to place inexplicable trust in people she got bad vibes from, however, and this irritated me. I think it created a lot of unnecessary tension, especially when she should have just listened to her gut and avoided said people. But otherwise I think the storyline is incredible, and the cliff-hanger at the end almost killed me.A wonderful follow-up to the awesome that is Obsidian, Onyx doesn’t suffer from the problems that many sequels do. Onyx is a must read for fans of Obsidian, and I recommend the Lux series to those who enjoy YA Fantasy and Science Fiction.