The theme of the story "The Midnight Visitor" is the consequences of greed and the importance of honesty.

Greed:
The story portrays the negative consequences of greed. The protagonist, Mr. Oliver, is a greedy man who is only interested in accumulating wealth. He does not care about the means he uses to achieve his goals. He is willing to cheat his clients and his partners to make more money.

Dishonesty:
The story highlights the importance of honesty. Mr. Oliver's greed leads him to be dishonest with his clients and partners. He cheats them by selling them substandard products and overcharging them. His dishonesty catches up with him when he is caught by the police and is forced to pay a heavy price for his actions.

Justice:
The story also highlights the importance of justice. Mr. Oliver's greed and dishonesty lead to his downfall, and he is punished for his actions. The police catch him, and he is forced to pay back the money he had cheated his clients and partners out of.

Lesson:
The story teaches us that greed can have severe consequences and that honesty is always the best policy. It also teaches us that justice always prevails, and those who do wrong will eventually have to pay for their actions.

In conclusion, the theme of the story "The Midnight Visitor" is the consequences of greed and the importance of honesty. The story teaches us valuable lessons about the consequences of our actions and the importance of doing the right thing.

The story highlights the theme that wisdom is more powerful than other weapons. Ausable’s intelligence is highlighted in the story. It is also based on the theme that one should not judge a person by merely his appearance. Ausable is fat and lazy but he is the most intelligent of all in the story.