Final answer:
The underlined transition in the given sentence shows a cause and effect relationship, connecting the speaker's silence to the outcome of the affair not being discussed again, thereby enhancing the flow of the narrative.
Step-by-step explanation:
The effect of the underlined transition in the sentence, "so I was silent, and when he entered the house I returned to the field, and the affair was never after alluded to?" is that it shows cause and effect. Transitions in writing serve to bridge ideas, helping to clarify relationships between sentences and paragraphs. In this example, the transition demonstrates how the speaker's choice to be silent leads to an outcome where the affair was never mentioned again. This use of transitional words enhances the flow of the narrative by connecting the actions of being silent and returning to the field with the consequence of the affair not being discussed in the future.