This idea of parallel universes, traveling in time and such have always fascinated me. Because what if I had made a different decision, what if I had more money, what if, what if, what if. And this explores that, Josie jumps at the chance to live a different version of herself. There is a lot of suspense in this one, with attacks and action right away. I connected with and felt for Josie. Her parents were going through a tough seperation and it can't be understated how hard that is. Especially since they both put her in the middle and to top it all off, her mom has been working non-stop and she just feels so isolated and alone. The science in this one really went over my head, but it seems well researched and thought out and though of course stretches the realm of possibility it is grounded in solid ideas. There is a whole other spin on this alternate universe that Josie decides to jump into and try the life of Jo. This world has monsters and they will claw and eat you if you are in the dark. But of course Jo didn't tell Josie that, and she also hid other details from her so that she is surprised while living Jo's life. The romance is interesting, and I liked seeing how nature and nurture made the parallel characters both alike and very different at the same time. I do see a difference between the two Nicks, but I still wish that I would have seen some growth with Josie that she wouldn't have based everything on a boy. I mean, I understand the hormones and attraction, but still. It was unreal how it all worked together and how it was all linked together. The worlds, the characters, the incidents that set it into motion was all crafted well. I also liked how the ending was, I was left with this sense of hope and closure. Bottom Line: Loved the premise and the characters were pretty well written.