The answer is the difficulty of determining what is real. Typical modernists had a loss of meaning in the modern world, so there themes included the question of "What is real?" There was a search for meaning in a world without God, and a search for self with a critique of traditional values.
Scout characterizes Boo as a petty criminal and a "malevolent phantom." Jem describes his neighbor as a monstrous figure, six-and-a-half feet tall with bloodstained hands. Dill must imagine Boo based on the descriptions his friends provide him.
You can't kill a wolves mate.
