This chapter handles the town's reaction to the crime before we see, in the next chapter, Joe's own actions following his crime.
Hightower's reactions in this chapter are central to understanding his character. Notice that when Byron Bunch discusses Lena's fate with him, Hightower refuses to offer his house as a refuge for her. He feels that he has suffered too much in the past and does not want to become involved in life again. Then after Hightower hears about the sheriff's finding Joe's trail, he feels some identity with Joe and is afraid that he is being drawn back into the stream of life. Even the fact that he feels something other than indifference to the fate of another person indicates that he is becoming involved with life again.
But he doesn't want to become involved, and even though he resists, Hightower is slowly being drawn back into life. At the end of the chapter, he reminds Byron to engage a doctor for Lena and casually offers to help if there is anything he can do. Thus through Byron Bunch, himself a person isolated from the community, Hightower is being drawn back into the stream of life even though he resists it at every turn.
In this chapter, it becomes apparent that Byron is falling in love with Lena Grove. Hightower still has the perception and sensitivity to recognize this fact and knows that it will only bring sorrow to Byron. So he tells Byron to leave this town, which he calls "this terrible, terrible place." Hightower has firsthand information as to how cruel and terrible the town of Jefferson is, and he fears for both Byron and himself. He prefers his life alone and has seen Byron live a life isolated from other people. He therefore fears that Byron is opening himself to terrible anguish and pain by becoming involved with a woman who is not accepted by the town.