The story spread like wildfire through Green Lake, and no children showed up for school the next day. Katherine wondered if she'd gotten her days mixed up when, suddenly, a mob led by Trout Walker burst into the schoolhouse. He called her the "Devil Woman" and yelled that she was poisoning children with books as the mob began piling desks in the middle of the schoolhouse. Katherine managed to escape the schoolhouse and ran to the sheriff's office.
By burning the schoolhouse and insisting that books are poison, Trout Walker shows that he believes education absolutely has a great deal of power to create change in the world—presumably, he believes education would make the children question their parents' racism. In this way, leaning on his power and money is a way to impede kindness and social progress.
The sheriff, drinking whiskey, greeted Katherine pleasantly and told her to calm down. She began to tell him about Trout Walker's mob, but he refused to hear anything bad about Trout. He told her she was pretty and asked her to kiss him, since she kissed Sam. Horrified, Katherine accused the sheriff of drinking. He explained that he always drinks before a hanging—Sam will hang for kissing her, as it's illegal for a black man to kiss a white woman. He asked Katherine for a kiss in exchange for sparing Sam's life, but Katherine ran away. The sheriff called out that God will punish her.
When the sheriff insists that God will punish Katherine for the kiss, he shows clearly that he believes that the divine powers are on his side and share his view of morality. However, remember Trout Walker's terrible boat. The boat alone suggests that these views are in opposition to the divine and to nature, which the novel tends to link to each other. In short, this tells the reader that the sheriff is wrong.
Katherine found Sam and told him they needed to leave. Sam agreed to leave Mary Lou behind and they started off in Sam's boat, rowing across the lake. However, he couldn't escape Trout Walker's motorized boat. The narrator states the facts: Trout shot Sam in the water and rescued Katherine, even though she didn't want to be rescued. When they returned to shore, Katherine saw that Mary Lou had been shot, as well. Since then, rain hasn't fallen on Green Lake, and the narrator asks the reader whom God actually punished. Three days later, Katherine shot the sheriff, applied fresh lipstick, and kissed him. She became Kissin' Kate Barlow and spent the next twenty years terrorizing the West.
The lack of rain on Green Lake after Sam's unjust death shows that the sheriff and Hattie Parker weren't correct; God and nature are linked and have a very different idea of right and wrong than most of the inhabitants of Green Lake. Katherine's decision to become an outlaw brings up the idea of vigilante justice, as she saw firsthand that the formal justice system wasn't actually that just. When she kills the sheriff, she's able to do a small thing to atone for Sam's death and begin to recalibrate the scales.