Question

Which themes does Mr. Shiftlet help reveal

Answer 1

By the end of the story, Lucynell had been abandoned, and Mr. Shiftlet, appalled at the corruption in the world and in himself, sped alone through the rain down the road to Alabama. 

Mr. Shiftlet had married the oblivious Lucynell and convinced her mother to give him some money and the use of the car, ostensibly so that he could take his new bride on a proper honeymoon.  Shiftlet and Lucynell had set off on their trip and stopped at a diner, where Lucynell fell asleep over her meal.  Shiftlet paid for her food, told the waiter that she was just a hitchhiker, and abandoned her there at the restaurant. 

Shiftlet continued on his way, depressed and tormented by his own behavior.  Hungry for company, he picked up a young boy who actually had never even asked for a ride.  He talked to the boy as he drove along, remembering stories of his "sweet mother" with melancholy regret, but the boy did not share his sentimentality; he shouted epithets about Shiftlet's mother and his own, and leaped from the car.  Shiftlet was stunned as he realized "the rottenness of the world", and as a heavy raindrops began to fall, he careened off down the road to Mobile.