Michael Prescott

Does that star-spangled banner yet wave ... One hundred years from now, America is a very different place. Central authority has collapsed. Infrastructure has broken down. Science and learning are slipping away. ... o'er the land of the free ... The northeast survives as a collection of independent city-states called freeholds. The freeholds keep to themselves. No one dares to cross the no-man's-land between them, territory infested with the horrors of this new world-eaters and skeeters, bleeders and bogeys. ...
and the home of the brave? No one ... until the summer night when a stranger arrives at Brighton Freehold, having crossed ten klicks of untamed ground. He comes with a warning. A great army from the south is on the march, destroying everything it finds. And the struggling seaside community of  Brighton, hard-pressed by famine and pox, is next in its path. Even in a future without hope, there is a place for courage.
For resistance. And for one last desperate stand ... In the year 2125 2125, a thirty thousand word novella, is the latest from New York Times and USA Today bsetselling author Michael Prescott.