As with many of Flannery O'Connor's short stories, the author intermingles a realistic portrayal of people living in the southeastern part of the United States with larger questions of good and evil.
The story begins with a husband, wife, children, and their grandmother going on trip by car from Georgia to Florida. At one point in the journey, the grandmother recalls an old plantation with a secret panel, behind which a cache of the family's silver was hidden. The grandmother's story spurs the children's curiosity and so they compel their father to turn around and try to find the old house. The fact that the plantation is near Toombsboro may foreshadow that this place will soon become a scene of death for them all.
While they look for the house, they have a car accident when the grandmother's cat leaps out of its basket and lands on the father, who is driving. As the dazed family gathers outside of the car, they encounter three men, one of whom is a notorious escaped criminal named The Misfit. The grandmother recognizes the man and immediately blurts out, "You're The Misfit!"
Unfortunately, now that the criminal has been recognized, he decides to kill the entire family. He has his two comrades kill the family, while The Misfit himself kills the grandmother.
One of the main issues raised by the story is what constitutes goodness. The grandmother seems to have the notion that a person's goodness can be determined by the way they appear. If they seem to be good, then they must have some goodness in them. As soon as the grandmother realizes that The Misfit intends them harm, she tries to convince him that he is a good man. She feels sure he comes from "nice people" and she is sure he is "a good man at heart" just by looking at him. The grandmother continues to insist to The Misfit that he is a good man, but finally he declares to her that he "ain't a good man". After The Misfit kills the grandmother, he declares that she would have "been a good woman...if it had been somebody there to shoot her every minute of her life." Thus, the story ends with this enigmatic statement which leaves the reader continuing to ask, "How do I know if the people I encounter are 'good' or not?"