Aiden starts talking. He talks about how it was like before the unleash of the infection in America. The infection spreads fast and people who are infected turn into zombie-like people and they attack the people who are not infected, infecting them and thus spreading it faster. After both his parents were, his 10 year older brother Tom took care of him.
The story shifts to one year ago, Tom and Aiden are walking through a overgrown street. They are wearing torned shirts which are covered in dirt and a bagpack. On Tom's bagpack is a hunting rifle, which isn't on Aiden's. Tom says that is still walking a while before they reach the camp. Aiden looks up to the bright sky.
Suddenly, a high and loud scream is heard. Tom shouts that it is an infected and they run to a building. They take cover inside it and look out of the window, seeing a group of infected running around. While Tom is loading his gun, Aiden says that they need to move on before they are surrounded. Tom disagrees and says that if Aiden wants to move up, he must wait until they have killed them all. While firing the first shot, Aiden hears a noise in the bag of the building. He thinks that those are militia members and Tom suddenly stops firing. He curses and while Aiden is freaking out, Tom says that he has to get upstairs and escape while he tries to repel the area. They will regroup at the camp they are heading to in a few days. Aiden denies that he is going to leave Tom behind, but Tom keeps saying that he will be fine.
Ultimately, Aiden goes upstairs and tries to leave the buidling, while evading the militia members. When he almost has escaped, he is spotted by a lone wolf of the militia and is attacked. Despites the fact that he has never killed anyone before, he kills the soldier which makes him freaking out. When some more shadows appear on the wall, he runs for his live, not looking back.