The world started being a living hell five years ago. At first, it was a normal animal virus that made them aggressive, something such as the rabies. Then it started getting into humans, making them aggressive too... And making them want human flesh especially. 

Military forces dedicated to capture as many zombies and humans as they could. They needed a cure, and their solution was to experiment with humans and do any means to get results.

You were a survivor with luck, until now.