A Knight of the Word is actually the second book in a trilogy called The Word and the Void. This second book of the trilogy is devoted to John Ross and his acceptance of the legacy in fighting that demonic evil fully explained in the first book.
It was eight hundred years ago when someone first started to fight the demonic evil in this urban fantasy: an evil called simply "the Void." Now it is time for John Ross to take up the fight in order to save humanity from living hell on earth. As such, he becomes the new "Knight of the Word." One of his first missions is in encouraging the young lady, Nest Freemark, choose the Word over the Void. Freemark makes the right choice in choosing the Word! Unfortunately, Ross is not able to stop the demons of the Void from killing the innocent, and this causes Ross to fall into full faith-crisis mode. As such, he decides to drop the fight and try to live normally.
Ross' decision to drop the fight doesn't work, however, when the demons of the Void are tempted to call him to their side. The demons find Ross in Seattle, Washington, and proceed to make his life a living hell anyway: threatening his family, his friends, his whole life. This is when Freemark makes her mark known to Ross yet again by showing up in his life. There is a demon invading Ross' dreams, and Freemark makes this demon known. Freemark arrives and convinces Ross to drop the "normal" charade and take up his true legacy.
In conclusion, I should say that this book truly blends reality and myth to create quite an interesting work of urban fiction. It cannot be classified fully as a fantasy novel nor just as a science fiction novel. It is a true blend with an exciting climax about the demon that haunts Ross' dreams.