In the beginning, it introduces a huge epidemic in the world, and the world haves extremely hot temperatures. There is then a huge apocalypse: the zombie apocalypse. The story centers on a group of survivors just trying to survive in the zombie world.
It was a really good book. I thought that it was filled with suspense and a good amount of action. If you're looking for a book where you never know when someone could die or someone could save the entire human race, then this is the book for you.