Alex, a sisteen-year-old girl with brian cancer, was hiking into the woods when an elecrtomagnetic impulse swept the country, destroying every electronic device and killing thousands of people between 25 and 60. Alex teams up with Ellie, an eight-year old girl whose grandfather was killed by the pulse, and Tom, a young soldier on leave from Afghanistan. They soon discover that the United States are in disarray and that among the teenagers who were spared, many have turned into flesh-eating monsters.
This book is action-packed and full with heart-thumping twists. It's almost as if it were divided into two parts: the first half featuring Alex, Ellie, and Tom fending off for themselves; and the second half, in which Alex is separated by her companions and finds shelter into the community of Rule. The first part was much more interesting than the second; even though the mystery of Rule was engaging, there was just no match. I wanted to learn more about Tom and what happened to him, and kept waiting for him to turn up.
The main character, Alex, is a strong girl who lost both her parents in a car crash a few years before. She was living with her aunt and fighting against brain cancer. At the beginning of the book, she's decided she will not undergo another cycle of therapy and has left her aunt's house to go hiking alone. Then, the mysterious pulse happens. The United States are now filled with teenagers turned into flesh-eating zombies. Well, there's not proper zombies, since they never died; but they behave exactly like zombies, so it's safe to consider them so.
Alex, Ellie, and Tom are left to fend off for themselves. They are actually very good at that. As a trained soldier, it's natural that Tom would have some experience in survival techniques. Alex, however, was way too good at that. The explanation given by the narrator was that she learned it all about from her father, but he has already been dead for years. Moreover, when the group finds shelter in the ranger's cabin, they could very well spend the winter there. Instead, they decide to move up north in order to find a "secluded" place where they can settle and start farming. But they already were in a secluded place... one provided with food and various equipment (including a generator!). Why would they need to leave? It's obviously a device to keep the plot moving, but I'd rather a more sensible motivation was given.
As for Alex's powers... I found that to be the weakest element in the plot. We already have a mysterious electromagnetic pulse (where did it come from?), mysterious killings (why did everyone between 25 and 60 die? Why only spare children, teenagers and old people?), and flesh-eating zombies (why were some spared?). You don't need superpowers, too.
Once Alex arrives in Rule, the narrative pace slows down considerably. It's obvious something's wrong there, and Alex is driven to find out exactly what. She's also alone, now, so she needs to find help. The book ends in a big cliffhanger - it would have been frustrating, had I not started to read Book 2 immediately.