Fortunato is 'the fool,' but Montresor is the true jester. He plays with Fortunato's pride and credulity. When he tells him about the Amontillado, he repeats he has doubts about its authenticity but says he will seek Luchesi's advice instead. He hints that things are not always what they seem to be and suggests that Fortunato's discernment may not be as keen as Luchesi's. This only kindles Fortunato's desire to show off his own expertise. So he follows Montresor, who dons his own mask and disguise. Another sign of dissimulation and ruse, but Fortunato stumbles blindly on.
Montresor then mentions Fortunato's cough and the ill effects of the cold and damp: "You are a man to be missed. For me it is no matter." Doesn't he mean here that he is indifferent to Fortunato's imminent fate? When he replies that a mere cold will not kill him, Montresor mutters, "True - true," but Fortunato is interested, rather, in drinking off a bottle of Medoc and ironically makes a toast to the dead in the crypt.
Fortunato's conscience should be pricked when Montresor explains his family's coat of arms, but he is too tipsy to make the connection. Nor does he wonder why he should be carrying a trowel under his cloak which he pro-offers as a "sign" of the masons. "You jest," he utters as he steps back, but insists on going on.
The lines of nitre spreading along the vaults Montresor refers to suggest a spiderweb, and Fortunato, of course, is the prey.
Montresor continually pesters Fortunato about the "cold" which he seems to have; the cold is both literal and a foreshadowing of the death which he will soon suffer. Fortunato thinks nothing of the continual questioning of his health, and proceeds blindly on into the cask.
As they progress into the cellar-like chamber, Montresor states, "Once more let me implore you to return. No? Then I positively leave you. But I must first render you all the little attentions in my power." Montressor is so distracted by the thought of the Amontillado, that he doesn't even respond to the implication that he will be left within the walls of the cask.
Lastly, in the final scene of this gruesome story, Montresor, as he seals up his victim within the wall, responds to Fortunato's request to leave with, "Yes, let us be gone." The kind of "gone" he means is obviously very different than that meant by Fortunato. Poe loved to play on words in this fashion. The victim pleas "For the love of God, Montresor!" to which the murderer replies, "Yes, for the love of God!" And so the deed is done.