If you haven'r read any of Eric Flint's 1632 series you need to start with the first, 1632. The ebook is free online from Baen. Starting with this book would be a waste of time. There's way too much history to plop right into this end of the story and not be lost. Other than that it is another excellent addition to the series and first by Flint alone in awhile. My only complaint is that it ends abruptly, cliffhanger, and the next book in the series is a few months out. Not much of a complaint really. I recommend the series and all it's books highly.