what subplot in encountered in chapter 6?

Hiram drives past the small village of Money, but since he cannot find the actual spot, he decides to stop at a random spot along the Tallahatchie River. Instead of doing much fishing, Hiram falls asleep but is awakened to the sounds of someone needing help in the water. Hiram rescues the person, and comes to find out that it is Emmett. He explains that he was bored at home and came to the river although he cannot swim. He was picking up rocks to throw in the water but he mistakenly picked up a snapping turtle and he fell in. After a couple more minutes of talk, Emmett leaves to go home for lunch and Hiram leaves as well. At home, he does not tell of his incident with Emmett as he knows that Grampa will not like it. Instead he lies about his line getting caught, but Grampa is quick to dismiss this as he wants to go out to lunch. As Hiram drives Grampa to the cafe, Grampa goes on a tirade about how desegregation is ruining the South and that the White Citizens Council has been meeting on what they can do to stop it.