The shock that Adam and Anne receive in this chapter is nothing to the shocks Jack receives, as he learns first that Judge Irwin accepted the bribe--a fact he had desperately hoped would not be true--and second that Anne has become Willie's mistress. The second shock is devastating to Jack, who has always placed Anne on something of a pedestal. The conflicting feelings of guilt and denial he feels when Anne confirms his suspicion at the end of the chapter will ultimately drive Jack to California, where he reconsiders his idea of responsibility and eventually arrives at the idea of the Great Twitch.
Thematically, perhaps the most important moment in this section comes when Willie meets Adam after Adam has agreed to accept the directorship. In this section, each man's moral philosophy is starkly exposed, and the two natural foils appear at their moment of greatest contrast. Willie proclaims that everything is bad, and that goodness is something man must create from badness. This idea is at the heart of Willie's frequent Biblical quotations, and would seem to explain how he can use such corrupt political tactics so guiltlessly--blackmail may be bad, but he uses it to create good. Adam, by contrast, still clings to the belief that good and bad exist in mutual conflict, and that certain things are good or evil by their very natures. (In this, Adam echoes the moral sense of Lucy Stark and Hugh Miller, who are each scandalized by Willie's decision to support Byram B. White in Chapter 3.)