In Go Set a Watchman, what is Jean Louise talking about when she says that her uncle Jack elects to "disappear in the mist?"
This occurs on p.201 in the middle of a long, and fairly convoluted conversation between Uncle Jack and Jean Louise. When she says "disappear into the mist" she means that he is choosing to be murky in his answers. He is choosing to make his answers unclear, and this confuses her.
At this point, she is upset (disgusted might be a better word) at Atticus and feels like she has been betrayed. She does not know this current Atticus - this one who goes to town hall meetings with racists and keeps books on suppressing the "negro." She is trying to express this to Uncle Jack, and he is trying to explain exactly what is going on. That is part of the problem - his explanation.
Uncle Jack almost talks in riddles. It takes him a very long time to get to the point, and even then, it is not direct.
At one point in the conversation they are standing in front of a mirror and Uncle Jack asks Scout what she sees. He says he sees two people. She asks if it is the tomboy and the woman, and he says it is more than that. It is at that point she says to him,
"Uncle Jack, I don't know why you elect to disappear into the mist..." (201).
She is referring to him, once again, not simply answering her question and getting to the point. By this point in the conversation he has been providing her with lots of anecdotes and stories, with the intention of getting to his point via the stories, but Scout has become increasingly frustrated with this method of conversing. She feels like he is simply giving her the run-around.