The setting is a Civil War reenactment, where a reenactor becomes possessed and kills some of his comrades. After a confusing red herring (the person killed has the same name as a missing boy the Winchesters go to investigate), the action picks up. The pacing is just like a show. It's a little complicated to explain the story, but I'll do my best with my end-of-the-school-year brain.
So the first guy is possessed, but then he kills himself. When the boys investigate, they see a rope burn on his neck, though there was no rope at the scene. Cass shows up and says the boys need to leave, that someone wants them there, and he thinks it's a First Witness, someone who broke bread with Christ himself. Well, with the rope, you can guess who. And the original possessed man isn't the last to be affected, so the brothers have to go on a search for the Judas Rope (recognizable by the way it's knotted). In addition, they have to deal with cursed pieces of silver, a sheriff with secrets, a creepy possessed black substance and demons who also want the rope. LOTS of action.
While there are undercurrents of the apocalypse arc, this reads like a standalone episode. I really liked Joe Schreiber's writing style, I enjoyed the setting and thought he captured the voices of the characters well. This is my favorite of the novels so far.