EMP Backdraft: Dark New World, Book 4 (Unabridged‪)‬

The Clan is reborn amidst pain and blood, scarred but stronger than ever, only to find that new threats face them from all sides. New friends also make their appearance, however, and Cassy must forge these into the beginnings of a greater alliance to have any chance of keeping their newfound freedom. The Clan must hurry because the looming Empire to the west may well be the least of their worries as the Dying Time continues all around them. America's invaders have made their way inland, threatening Cassy's alliance before it even really begins....