Holy cow! This book was awesome! I have been on such a contemporary kick that I have been neglecting all of the other genres that I used to love. Including fantasy and science fiction. Oh, how foolish I have been. 3:59 reminded me just how much I love these genres. I need to go find other fantasy books to read right away. I haven't experienced a Gretchen McNeil book yet, but I have no idea what I was waiting for. This book is easily the best written, most exciting book I have read all year. 3:59 is very science heavy, but I never felt lost or confused by the scientific jargon. You could tell that Gretchen clearly did her research and she explained everything we needed to know really well through Josie and Penelope. (the two science-y ones in the story.) 
 I loved that even though there are two doppelgangers, Josie and Jo in this story it was only told through Josie's point of view. It would have been easy to switch back and forth between her and Jo in the beginning of the book when they were first seeing each other through the mirror, but I was so excited that the point of view never switched. I thought it really added to the story to have Josie put everything together for herself. Josie is such a smart girl- brilliant really, but she is also just a teenage girl that recently got dumped by her boyfriend. So when she looked in the mirror and saw her boyfriend happy with her other self, she saw what she wanted to see. That is what made her go from a good character to a great character in my mind. That sounds silly, doesn't it? but she was so realistic. She isn't perfect, she made some mistakes, but she more than made up for them in the rest of the book. 
 There are so many twists and turns in 3:59, I couldn't even predict half of them. Which made for such an exciting read! I couldn't put this book down. I was on the edge of my seat for the whole thing. When I had to stop reading to run errands or to do some work, I was actually annoyed that real life was interrupting my reading time. Gretchen McNeil knows how to write creepy. Man, the Nox was something I would have nightmares about. I would hate to live in a world with them. But they were fascinating. Everything in her world was actually. If you are a "world building" fan, you will LOVE 3:59 because the detail and description in this book is grade A. I think 3:59 is a must read book of 2013. Whether you are a fan of fantasy and science fiction or not, you need to read this book.