“The Tell-Tale Heart” and “The Masque of the Red Death” both tackle the themes of death, sin and guilt, but in very different ways. Both use irony to tell their stories.
In both stories, death takes innocent victims. The narrator kills the old man in “The Tell-Tale Heart” because of his supposedly evil eye. The people in “The Masque of the Red Death” are dying from a plague. The deaths have something else in common: murder.
In “The Tell-Tale Heart” the narrator murders the old man in cold blood—he commits an overt sin. In “The Masque of the Red Death” Prince Prospero murders his people by a sin of omission. He does nothing while they are dying. The other sin he commits is gluttony. Prospero throws a lavish party for all of his friends while his people suffer. He has the money to try to help them, but he does not.
When his dominions were half depopulated, he summoned to his presence a thousand hale and light-hearted friends from among the knights and dames of his court, and with these retired to the deep seclusion of one of his castellated abbeys. (enotes etext p. 4).
In “The Tell-Tale Heart” death is more direct. The narrator feels that he is very clever because he kills the old man and buries his body under the floorboards. He, like Prince Prospero, feels that he is completely justified in doing this.
Madmen know nothing. But you should have seen me. You should have seen how wisely I proceeded—with what caution—with what foresight—with what dissimulation I went to work! (enotes etext p. 4).
However, guilt overcomes the narrator in “The Tell-Tale Heart” in a way that it does not ever really capture Prince Prospero. The narrator descends farther and farther into madness, until he finally confesses because all he can hear is the murder of the old man’s “hideous heart!” When death confronts Prince Prospero, he reacts arrogantly.
“Who dares?” he demanded hoarsely of the courtiers who stood near him—“who dares insult us with this blasphemous mockery? (p. 6)
There is a certain amount of irony in each case. The narrator in “The Tell-Tale Heart” and Prospero in “The Masque of the Red Death” are both essentially defeated b their own egos. The narrator in "Heart" thinks he is smart, but his guilt traps him. Prospero thinks he can outwit death, but death finds him.