Fire from the Sky is a post-apocalyptic fiction by N.C. Reed.

Clayton Sanders left home the minute he had his high school diploma in hand. He waited that long only because the Army wouldn't accept him without one. Now, 10 years later, he's home. Home with no warning, no advance notice, no anything after being gone 10 years with almost no contact with his family. Home carrying a secret that is burning him up from the inside. A secret that has pushed him to the brink, forcing him to become a criminal in order to be where his family needs him to be, even though they don't realize it yet. Because, Clayton knows something they don't. Something that hasn't happened, but will. Something that will burn everything it touches. And change the face of the world forever.

Excerpt from Hostile Fire:

William Shirley watched as the people he had assembled for what others were calling a "reconnaissance in force" gathered their equipment and shook down their ranks. He had combined three different "squads" into a new platoon of 31 people, adding that force to an established platoon of 35 more. They would head north in a small string of vehicles that included a school bus to investigate the situation north of the Alabama-Tennessee state line.

Shirley's group, the self-entitled "North Alabama People's Militia", had lost a great deal of personnel and equipment in that area, and he wanted to know why and to who. It was inevitable that the group would have to head north at some point in search of supplies. They had stripped their own area nearly bare over the last few months, and moving too far south was out of the question. While he considered Decatur to be part of their "territory", moving any further south than that risked a confrontation with the gangs of Birmingham, something his group lacked the strength for. There had already been a few skirmishes between the two groups, and Shirley was determined to avoid any more clashes with such a large and vicious outfit. 

So, north it was, into rural middle Tennessee. The area immediately north of the line should be safe enough and resource-rich. That area was full of farms and livestock operations that should yield a good amount of food for his operation, and he meant to have it. If they waited too long, then someone stronger, either from Nashville or perhaps Chattanooga, might move into the area and declare it theirs. If the Militia wanted that territory and the goods it might provide, they had to act soon. 

And tomorrow should be soon enough. Sixty-six heavily armed troops would move north and keep moving until they found opposition or else found something worth sending word for trucks to carry it back to the compound. If he was lucky, they would also find out who had killed his niece and his fellow board member's son. He looked forward to that. When he found whoever had killed his people, he would show them what a mistake they had made.