Edgar Allan Poe claimed that a writer shouldn’t put pen to paper until he knows the ending (source). “The Cask” is a shocking example of this idea in action. There are tons of significant aspects of Poe’s ending. We’ll get at some of the bigger ones.
First, Fortunato finally reveals Montresor’s name; we now know that he is, or claims to be, part of the Montresor family buried in the catacombs. (See “Character Clues,” and the Montresor Family’s “Character Analysis” for the significance of his name.)
Second, the jingling of Fortunato’s bells is pretty important. As Montresor fills in the fatal wall and Fortunato sobers up, Fortunato cries out and rattles his chains, laughing nervously at Montresor’s “excellent jest.” When the penny finally drops, Fortunato’s pleas get more and more desperate: “For the love of God, Montresor!” But Montresor meets all of Fortunato’s begging with mockery, leaving Fortunato horribly silent.
Terrorized, Fortunato knows there is no way out: the final stone will be inserted, and his air will soon run out. Nonetheless, he can’t stop − Fortunato must assert that he still lives. The jingling is a last ditch effort at communication that makes Fortunato’s death (which we only hear off screen) all the more poignant – it shows us what he’s been reduced to.
Third, and just as chilling, if not more so, is Montresor’s failure to be sickened by Fortunato’s jingling. When he says, “My heart grew sick –,” he teases us cruelly – à la Patrick Bateman. The next few words (“on account of the dampness of the catacombs”) tell us that he isn’t sick because of his crime; he’s bragging that he got away with it. Unless you think he’s just hiding his real feelings of remorse.
Now for the final line: “In pace requiescat” (89). This means, “may he rest in peace.” Critic Elena V. Baraban points out: “The phrase is used in the Requiem Mass and during Last Rites” (source.) It’s what a priest says to a dying person, after the dying person confesses his sins. By saying this phrase, a priest can forgive the dying for everything he or she has done wrong.
Baraban claims that this proves Montresor’s story isn’t his own confession. Instead, he’s taking on the role of priest, forgiving Fortunato for his sins, which Fortunato can’t confess on his own, because (obviously) he’s dead. Totally creepy.
Unless Montresor really means that “may he rest in peace?” If Montresor is sincere, and means the words literally, then maybe he feels sorry for what he did, and really wants Fortunato to rest in peace. What do you think? For more discussion on this, see Montresor’s “Character Analysis.”