Montresor begins his chilling confession by revealing his thirst for revenge against Fortunato, a friend and fellow nobleman who has repeatedly insulted and wronged him. Instead of a verbal altercation, Montresor seeks calculated retribution, meticulously planning to leave no traces and ensure that Fortunato knows his tormentor.
The carnival season provides the perfect disguise for Montresor's scheme. He encounters Fortunato, a renowned wine connoisseur, dressed in a flamboyant striped costume with bells and clearly intoxicated. Recognizing an opportunity, Montresor feigns concern, claiming to have bought a questionable cask of Amontillado, a rare sherry, for the price of a special vintage.
Fueled by arrogance and pride in his expertise, Fortunato dismisses any possibility of being fooled. Montresor, sensing this, pretends to hesitate, suggesting another supposed connoisseur, Luchesi, for advice. This only inflames Fortunato's ego further. He mocks Luchesi's abilities and declares that such a wine cannot be found during carnival season.
Montresor then tries to dissuade Fortunato from venturing into the damp, cold vaults where the wine supposedly rests. He expresses concern for his health, pretending to deter him. However, intoxicated and brimming with arrogance, Fortunato refuses to be swayed. He insists on accompanying Montresor, determined to prove his expertise.
They gradually descend into the Montresor family catacombs. Fortunato begins to develop a cough, which is brought on by the dampness and oppressive atmosphere. He quells it with the Medoc wine Montresor offers him.
As they go deeper, Montresor reveals the familial coat of arms—a shield that portrays a human foot crushing a serpent “whose fangs are imbedded in the heel"—and the motto etched on the wall: "Nemo me impune lacessit," meaning "No one can harm me unpunished." Montressor fails to comprehend the true nature of their descent, unaware that his own pride and arrogance have led him into a trap carefully constructed by his vengeful companion.
They continue to go deeper into the Montresor catacombs as the air thickens with a damp chill and the suffocating nitre grows increasingly dense. Fortunato's coughing intensifies, but he silences it with another drink. His drunken stupor deepens, oblivious to the danger lurking within the damp walls.
As they progress, Montresor reveals a petrifying sight—a crypt lined with human bones, dripping with the nitre. He suggests another drink. Fortunato, unaware of the symbolic weight of their surroundings, raises his glass in a bizarre gesture, claiming it belongs to a secret brotherhood, the Freemasons.
Montresor, seizing the opportunity, reveals that he too is [a] mason. He produces a trowel, a tool for construction, as a symbolic gesture. This confuses Fortunato further, but their journey continues, deeper into the intricate vaults.
They reach a dark, ominous crypt. Within lies another chamber, narrower and grimmer, its walls adorned with gruesome decorations of human remains. Beyond this lies a final recess, pitch-black and foreboding. Montresor mentions Luchesi again in a final attempt to dissuade Fortunato. But the intoxicated Fortunato insists on pressing on.
With his flickering torch, he disappears into the darkness. Reaching the end, he finds himself trapped, chained to the cold, unforgiving stone. Montresor's mask slips, and he taunts Fortunato, drawing attention to the oppressive nitre, a reminder of the inescapable tomb he has constructed.
Panic replaces drunkenness in Fortunato's voice. His frenzied pleas for release are met with cold indifference. His cries of "Amontillado!" now hold a desperate hope, a final plea for the wine he was lured with.
Montresor, unmoved, gathers debris from the scattered bones. As he builds the wall, brick by brick, Fortunato's desperate cries transform into whimpers. The intoxication has lifted, revealing the terror of his predicament.
Row after row, the wall rises, slowly sealing Fortunato's fate. In the dim light, his figure recedes, his screams turning into horrific, muffled echoes. Montresor mocks his terror, mirroring his cries in a twisted parody of empathy. Finally, silence descends, the weight of Fortunato's demise settling upon the damp air.
By midnight, the wall nears completion. Only one brick remains. As Montresor prepares to seal his victim's tomb, Fortunato’s low, cynical laughter pierces the silence. His voice, now laced with despair, acknowledges the "joke" but pleads for release. He claims people are waiting for him, a desperate attempt to deny the terrifying reality.
Montresor mocks him, echoing his words without offering answers. When silence descends again, he calls out, disappointed by the lack of response. His morbid satisfaction fades, replaced by a wave of nausea brought on by the damp and crushing atmosphere. He extinguishes his torch, plunging the recess into eternal darkness, and lays the final brick, sealing Fortunato's fate forever.
He concludes the tale with the detail that the wall remained undisturbed for half a century. His final words, "In pace requiescat!" (“May he rest in peace”) are delivered in Latin, a hollow offering to a soul condemned to an eternity of darkness and despair.