Throughout the many acts and scenes of this plot, one thing stays consistent: the thematic paranoia that makes people point fingers at one another. First and foremost, they point fingers at the "other." Instead of realizing that all humans are capable of conspiracy or evil, the people who are established in their town are more likely to blame newcomers and outsiders, quickly moving into a dangerous, "us versus them" mentality, a mentality which the novel explores through variation on that theme.
The strangers are treated very poorly, and the English law that defines life among the civilians is denied to those whom the community regards hostilely. The altercation leads to a symbolic punishment: public humiliation and exposure. Then, they punish a woman among them. They disgrace her in public, allowing her to be violated in public by those who regard themselves as "the good guys," so to speak (obviously, the scene is proof that the villagers are quite monstrous). They shave her head, so that she will not be able to fit in for a long time. She will be a permanent target for hatred.
Afterward, the novel shows that a community that tolerates this kind of hatred will become paranoid and twisted up. Walter is a perfect example of this. Although he understands quite clearly why Jordan wants the field for his sheep, he claims them for his agriculture. He quickly judges others, often running the pillory, but he himself gets drunk and eats magic mushrooms. Unsurprisingly, the town ends with this chaotic season of self-destruction, and this time, it is Walter who lights the last fire. He is the agent for the town's destruction.
