This story is not about the investigation or detection. The murderer Montresor narrates the murder himself. The first intriguing bit in this poem is the poet's inability to explain the reason behind his actions. The mystery in this entire poem is the reason behind the murder. The reader is left to judge the motives behind the killer's moves. Except for the phrase "the thousand injuries" and "insult", there seems to be no probable cause to the writer's anger. Thus, the narrator tries to win over the audience from the very beginning; it is with this idea that the author is bound on setting bait to trap his victim after which he will take his revenge. However, the reader is unable to get a clear picture of what wrong has been done to Montresor.
By luring Fortunato who is a connoisseur of wine "in the matter of old wines he was sincere", Montresor claims to have found a pipe of Amontillado which has a rare and valuable sherry. The odd thing about the connoisseur's behavior is how easily he becomes drunk. Not only that but he is drunk enough to be incapable of recognizing De Grave "He emptied it at a breath" which seems to be a strange way for an appreciator of fine wine to treat such a vintage. At this point, Fortunato seems more like an alcoholic than a wine expert.
The short story is very biased in most aspects. Monstresor presents his own perspective and prevents the reader from truly knowing anything about the other character in the poem. The narrator makes himself seem wronged by stating the injuries had been "borne as best as I could." Forunto's skill as a wine taster is shown as "a weak point." Thus, the reader is never presented with a true view of anything except what Monstresor wishes us to see.
The setting of this story is vital for the understanding of the work. There are two important settings in the Cask of Amontillado: the carnival and the catacombs. The carnival sets the picture of what the murderer has actually planned. Also the "dusk" in the "supreme madness of the carnival" shows how Montresor will be able to conduct his evil plan unnoticed. The graphic description of the catacombs "damp ground of the catacombs of the Montresors." Such vivid pictures allow the reader to place themselves in the exact situation and feel what the characters are feeling.
Poe's perverseness is evident in the humor of this poem. There are certain lines which show that Montresor is actually enjoying every moment of this planned murder. These include the constant references to Fortunato's "cough" and the "severe cold with which I perceive you are afflicted" is a mockery. This is because the narrator knows that the wine taster would be insulting his profession if he goes back on this opportunity to taste this rare and vintage wine. Thus, he says these lines only for his amusement, knowing full well that the victim will continue to follow his desired plan.
There is a great degree of irony in the story. This is evident from the first line of the poem that shows how the writer has tolerated a "thousand injuries" but would not be privy to any kind of insult. This makes the reader wonder how any individual can withstand injury quietly but take revenge against an insult. The dramatic irony in this story is how Fortunato is completely oblivious to the deviant plans that are in store for him. He is fooled by the smile of the writer "he did not perceive that my smile now was at the thought of his immolation." Also, while