The quote at the beginning of the novel, which includes the title, sets the stage for the plot. It's taken from the Anabasis of Xenophon, which concerned an army finding itself alone in suddenly hostile territory,and conducting a fighting withdrawal against overwhelming odds. (Interestingly enough, this basic plot concept will also be used in Paul Kearney's upcoming epic fantasy, The Ten Thousand.) Both Kearney and Knight employ realistic military background in their stories, but within totally different frameworks, as Knight's work features a future alien-invaded Earth, not a fantasy world.
This particular volume finds protagonist David Valentine leading one branch of an attempt by the human resistance movement to establish a freehold in the Appalachian Mountains. But there are traitors and double agents everywhere, and the alien Kurians are nothing if not clever and implacable adversaries. Valentine's superiors find themselves trapped in enemy land and trying to escape with their army intact to fight another day.
Knight's strengths lie in his ability to create a military resistance that seems completely plausible because of the thought and detail used to describe it. He couples this with excellent characterization, and the result is that a reader not only believes that Earth could be like this if occupied by an alien species, but the reader pulls for the three-dimensional and very sympathetic humans who are trying to survive and overthrow the tyrannical new order.
I will admit that the novel opens slowly, if one is expecting non-stop action, but Knight carefully constructs the military machine that is necessary to allow a cross-country journey and an attempt to finally go on the offensive against the alien nemesis. The pay-off is worth it, as the last 150 pages are quite suspenseful and harrowing, and portray Knight at his best.
Vampire Earth reminds me of David Gerrold's War Against the Chtorr, but unlike that series, the reader is rewarded with a book of consistently high quality every year, not a never-ending wait. It deserves a wide readership.