How does paragraph 3 mainly add to development of the plot?
Tell tale heart

The plot is about a man who wants to murder another man but doesn't want to be caught and punished. We have to assume that he intends to commit a perfect crime, even though the narrator does not say as much until after he commits it and hides the body under the floor boards.

Explanation:It tells the famous Edgar Allan Poe story of the deranged boarder who had to kill his landlord, not for greed, but because he possessed an "evil eye." The killer is never seen but his presence is felt by the use light-and-shadow to give the impression of impending disaster.