In the book To Kill a Mockingbird, young Scout arrives upon the scene when she is worried about her father. She and her brother Jem are both present. Atticus is standing in for the sheriff who is out at the time. He is aware that Tom needs protection.
The men gather around Atticus and demand that he move and allow them to get Tom. They are a lynch mob who plan to take justice into their own hands. When Jem is pulled back Scout becomes upset and moves to the front of the crowd.
Scout becomes the voice of innocence who does not see the men as a mob but as individuals. She begins to ask Mr. Cunningham about his son, and she is puzzled by his actions. By speaking out Scout inadvertently stops the men from being caught up in mob reality and moves them apart as individuals. Mr. Cunningham feels awkward as he is separated out from the others and is forced to think of himself in his individual role with Scout and Atticus. Scout's actions defuse the mob mentality.
She protects Atticus by being there because the people there were on the edge of attacking Tom in the first place, Scout just convinced them that it was wrong by basicaly touvhing Mr. Cunningham's heart, which he led everyone else away.