The neighborhood looks almost normal that morning. The grass is still cut. The mailboxes still stand at the ends of the driveways. And three houses down, a man is standing at his mailbox who has not moved in four minutes. He is not opening anything. He is not holding anything. He is not waiting for anyone. Emily is the first one in the family to notice that the angle of his head is wrong.

The collapse killed most of the country in the first ten days. The people still walking are not all the same kind of people anymore. Most of them are simply terrified civilians trying to figure out what comes next. A smaller number are not. The Smith family does not yet have a word for what is standing in front of Mr. Halverson's house, and the moment Mark steps off the porch to check on him is the moment the threat landscape of their entire lives changes. ...