During the thunderstorm scene (which ends with the narrator's father dying from fright), the narrator uses imagery, as seen in the following passage:
It had been a day of great heat, and in the afternoon the sky had grown low and heavy and black. It felt almost chilly in the house, and my father was sitting wrapped up in the rocking chair. The rain began to fall drop by heavy drop, beating like a hundred fists on the roof. It grew dark and I lit the oil lamp, sticking a pin in the wick, to keep away bad spirits from the house.
The narrator uses several types of imagery here to bring readers into the scene. The descriptions of the “great heat” outside and “chilly” temperature of the house help readers feel the scene, the description of the sky growing “low and heavy and black” helps readers see the scene, and the description of the rain falling “like a hundred fists on the roof” helps readers hear the scene.
This last description is also a simile. In comparing the rain to punching fists, Naipaul prepares readers for the way that the narrator’s father will, due to fear and paranoia, interpret the sounds of the thunderstorm as people waiting outside to kill him (leading to him drying from fright).
One of the ways that the narrator’s family learns that people are trying to kill the narrator’s father is by hearing menacing voices surrounding their house at night. The narrator uses imagery to capture this experience, as seen in the following passage:
Sometimes there would be two or three of these voices, speaking from different directions, and we would sit awake in the dark house, just waiting, waiting for the voices to fall silent. And when they did fall silent it was even more terrible.
My father used to say, ‘They still outside. They want you to go out and look.’
And at four or five o’clock when the morning light was coming up we would hear the tramp of feet in the bush, feet going away.
The narrator uses auditory imagery here when describing the voices coming “from different directions” and “the tramp of feet in the bush” in the morning when the people depart. He also uses visual imagery when describing the “dark house” in the night followed by the “morning light” coming up at dawn.
All of this imagery combines to help readers experience, at the sensory level, the fear that the narrator and his family are experiencing in this moment, surrounded, as they are, by potential killers. It also helps explain why the narrator’s mother ends up leaving the house, abandoning her son in the process.