I am still thinking about this book and the possibilities of what I didn't understand when reading it. Set in a futuristic holo-city with heavy AI and robotic tones, you have to finish the book to get the full effect of the suspense and shock of its twists and turns. It starts off very slow with the world-building meticulous in introducing concepts my brain didn't quite grasp at first. It was difficult to get into the mindset of the advanced technology being put forth and what the actual conflict was going to be. The first 100 pages were incredibly boring to me but, I was flipping back to them towards the end because they are highly important. Around page 200 you really start to see the characters develop as their truths are revealed. Every time you think the story is going one way, there is a twist that puts you down a different path of possible outcomes. Where one sister's story is singularly focused and a rush of emotions, the other's is slow and calculated. The book ends on a cliff-hanger but, as a stand-alone, it demands more of the reader even after the book is returned to its spot on the bookshelf!