Birmingham's first entry into his three book series called Without Warning was tons of fun largely due to the premise and pace. And it ended with an exciting cliffhanger that is only partly capitalized on in After America. This second book picks up the action in 2006 following an event that largely took out the people of North America three years earlier. We learn that the parts that were impacted can now be re-settled and they have become hotly contested which produces the majority of the action.
The author has tied up some plot mess and loose ends created in the first effort while focusing on the more developed and enjoyable characters. But for me the best parts of the book involve the battles to reclaim the Declared Security Zone of New York which provides amazing images of conflict on Manhattan. I work on Madison Avenue so it was incredibly interesting to imagine the war zone Birmingham has created. Several other plot lines continue but they are not really developing or are as interesting. And I am having a hard time with The Echelon 'super agent' - the character seems unnecessary to this point.
Overall one has to hand it to Birmingham, he has created a complicated and scary new world that is intriguing to witness. I only ask that he focus even more in the third installment and keep the action coming along with some explanation of the original event.