The theme of Roald Dahl's short story "Poison" is racism. The characters in the narrative are Harry Pope, Timber Woods and Dr. Ganderbai.
The story is narrated by Woods, who, upon arriving at Pope's bungalow, witnesses his friend lying paralyzed in bed and drenched in perspiration. Pope claims that he is in mortal danger because a deadly snake is crawling on his stomach underneath the sheets and he is too terrified to move. Woods then summons Dr. Ganderbai, an Indian doctor, who proceeds to administer to the patient. It turns out later in the story that there was, in fact, no snake lying on top of Pope's stomach. When the doctor suggests that the snake was just a figment of Pope's imagination, Pope turns hostile and hurls racial slurs at the doctor. The title of the story alludes to the point that people are the most venomous of all creatures.