It's Carnival in Italy and good wine is at a premium. Montresor uses stratagem to lure Fortunato into his underground vaults to exact his revenge. Fortunato, ever so happy to display his wine wisdom, agrees to accompany Montresor into the catacombs to test the wine, hoping to expose Montresor as a fool, ironic considering Fortunato's wearing the fool's costume.
There are two things that allow Montresor's plan to succeed: (1) Fortunato is extremely drunk; (2) Montresor is a master of reverse psychology and irony. Numerous times, he cautions Fortunato about his cough and declares his wish to go to Luchesi--whom we know little of other than Fortunato thinks he's an "ignoramus." This mention of Fortunato's rival makes him all the more eager to prove Montresor's imbecility in buying Amontillado from a huckster.
The two proceed down the ancient corridor when, suddenly, Montresor chains Fortunato to a wall, where he has remained ever since.
Once the wall is about half-way up, Fortunato begins screaming, and Montresor mocks him. Fortunato calms, and says, 'A very good joke indeed,' probably with his last bit of hope. Montresor humors him for a moment, but soon Fortunato realizes it's not a game. He screams, 'For the love of God, Montresor,' and Montresor repeats his words. There is silence.
Montresor, who wants Fortunato to continue to beg, becomes impatient and calls out to Fortunato, trying to provoke him. The man does not respond. In hopes of getting Fortunato to respond in some way, Montresor throws a torch into the only open area left. He hears the tinkling of bells. He says his 'heart grew sick' but only on the 'account of the dampness of the catacombs,' and he finishes building the wall. Then he says the events happened fifty years prior. He concludes his reminiscence with 'rest in peace.'