How does the dialogue contribute to the plot of the story?

Which three sentences in this excerpt from arthur conan doyle's "the contest" suggest that the author's tone is mocking?

Ill she not be here anon? is she not hurrying to upbraid me for my haste? have i not heard her footstep on the stair? do i not distinguish that heavy and horrible beating of her heart? what is the effect of parallelism in this excerpt? it emphasizes usher’s misunderstanding. it emphasizes usher’s love for his sister. it emphasizes usher’s psychological fixation. it emphasizes usher’s melancholy nature.

Lens quotation: "character is what you are in the dark." -dwight lyman moody