The Cask of Amontillado is a short story on the topic of revenge that deals with the frightening concept of being buried alive (although in this case it is more of an immurement, or being buried behind a wall). This story, like a couple others by Poe including "The Tell-Tale Heart" is written from the (first person) perspective of the murderer. It is a very dark story and, even at the end, the murderer does not seem to have any remorse.
One of the main aspects of the story is the irony found throughout. Irony is defined as the use of words to convey a meaning that is different from the literal meaning. One example is the name Fortunato (given to a man who meets a very unfortunate end). Another is the fact that the story, dark and disturbing, takes place during the joyful time of Carnival. Google searching the title of the story (in quotation marks) and the word irony will help you find a number of examples.
Poe explained his style as arabesque, one of horror and torment. Irony and wit are part of the grotesque playfulness of this arabesque and the pattern has balance and integration of these elements as psychological tension and horror parallel the action and dialogue.
Much like the winding catacombs that narrow and darken, the workings of the narrator are twisted and darkly sinister. In fact,the narrative is controlled by this vengeful narrator whose obsession with revenge finds grotesque humor in ironic jesting with Fortunato about his being a mason--not the secret society member, but a bricklayer who is about to entomb his victim. With a perversely feigned concern for his victim's health, the narrator urges Fortunato to turn back: "...it is very damp. Once more let me implore you to return." Then, the narrator adds to the horror:
No? Then I must positively leave you. But I must first render you all the litttle attentions in my power.
This torment of Fortunato increases as Montesor lays down the tiers of bricks which soon entomb the connosieur. Still Montesor calls to his enemy, then walling him in further, increasing the psychological tension. Finally, the narrative has completed its windings and Fortunato begs his tormentor: "For the love of God, Montresor." With grotesque irony and the final arabesque, ornamentation of horror, Montesor responds, "Yes,...for the love of God" and hastens to "an end of my labor."
This story was part of the American Gothic movement, stories that featured the dark side of human nature, and were often set in eerie or creepy places. The catacombs definitely fit that description, and Montresor's resolutely and calmly planned revenge fit the feature of exploring the darkness that humans are capable of.
It is also written in first-person, which allows the reader to get inside the narrator's head. This way, we know the sinister thoughts of Montresor, and know he wants revenge. We just don't know how until the narrator himself reveals it to us. That first-person angle adds suspense, because the action is revealed as it occurs, from one perspective only. The narrator's voice and style is also very distinct; Montresor is a calculated, calm, unrepentant murderer, and it shows in his commentary.