The most obvious change in this edition is that most of the foreword has been moved to an afterword. In the original, the foreword laid out much of the story, and then the main text backtracked to lead up to events mentioned in the foreword. While this was helpful in a book introducing a fictional universe, it did lean toward introducing spoilers. Now that there are several books set in "The Smolder" (a time when freedom and wisdom and knowledge have all been reduced to embers), it seemed like a good time to go back and wrestle this first one into better shape. In addition to moving the foreword back, I sliced and diced a little bit in the main story, combining a few chapters, smoothing out a couple/three rough spots, and cutting a few passages that slowed down the narrative or that were extraneous. The goal was to produce a book that told the same story, but better, without being jarringly different to readers who liked the original edition.
The Smolder books aren't written to be read in any particular order. The Birdwatcher and The Unexpecteds are set in the same general area out West and happen at roughly the same time and share a few characters with one another. The Smolder, set at the same time, happens back East in New York. The Hidden introduces a prison camp system unknown to characters in the other books, and Notes From Hiding picks up the story of children born to characters in The Hidden.
In other words, it isn't a series quite as much as books that are set all in the same war, but on different fronts. The bad guys are all racists and totalitarians, who expect conformity in their 'citizens' - and a different conformity for each breed of human. People, however, aren't made to fit into templates like that. And God, of course, always has a remnant, and the schemes of men can't stop Him from prevailing in the end.
Some reviewers have called this series "hopeful dystopian" stories. I suppose that's as good a description as any. It even works on multiple levels. I've read quite a few accounts of life under the Soviets and Nazis and other communists and secular socialists, and I've read quite a few accounts of Christian martyrs who were killed simply for their faith, and you will see some of that reflected in these books, with the understanding that for the Christian such suffering doesn't mean defeat. (If you read the New Testament, you'll find it can even mean greater rewards in the long run. Really. Go see for yourself.) On the other hand, I love to write clean romance, and stories about friendship and loyalty, and of victories over bad situations, and you'll find that in here, too.
At Amazon, both editions are available in Kindle editions. Elsewhere, only the revised edition will be available in ebook, once all the catalogs get caught up. Both editions are available everywhere in trade paperback.