The book takes place in western Washington after a virus turns half the world's population into zombie like creatures. They are called rogues. The people who were immune to the virus are called survivors. Typically, these people formed into groups that turned into what are called "family communities." There are groups called survivalist gangs who find the family communities, decide if raiding them is worth their time, kill any adult they can get to, and take "worthy" children and whatever supplies they can carry. They use the children as free labor and the kids who have promise, they brainwash into working for them. There are multiple survivalist gangs around, but they never get too close together. They tend to be in old cities like Seattle, New York City, and Chicago.