Due to an insult received from Fortunato, Montresor contemplates revenge. He continues to pretend to be his friend, concealing his true intentions. One day, during the carnival celebrations, he encounters Fortunato dressed as a jester and completely intoxicated. Seizing the opportunity, Montresor takes advantage of his state and invites him to his cellars under the pretense of verifying the authenticity of an Amontillado, a highly prized wine, of which he is uncertain.

Fortunato, being a great enthusiast, does not hesitate and follows Montresor in hopes of discovering a rare wine. They head towards Montresor's palace. Upon arrival, the cellars are utterly deserted. Montresor has made sure to send his servants away to execute his sinister plan undisturbed. The two men descend into the cellars, reaching the dark catacombs of the Montresor family, a daunting place where the remains of his ancestors lie.

They reach the deepest part, where the air is very damp and cold. Montresor, noticing Fortunato's cough, displays feigned concern and offers him wine under the guise of strengthening him, but in reality, he only aims to further intoxicate him. Fortunato, with a smile, accepts the wine, unable to refuse such a gesture of 'kindness.'

The environment grows increasingly macabre, with wine barrels lying next to human bones. Upon reaching a hidden niche, Montresor quickly chains Fortunato to the wall, unbeknownst to him what is truly happening. Montresor begins to wall up the entrance to the niche with stones and mortar. When Fortunato begins to realize the gravity of his situation, it is already too late, and his pleas are in vain.

When only a small opening remains with the last stone to be placed, Fortunato attempts one last desperate ploy. He tries to cling to humor, to mockery, hoping to shake Montresor, to convince him to stop. But Montresor remains icy and completely seals the niche. The catacombs return to their usual silence, while Montresor emerges into the open air, finally feeling satisfied. But in the following years, his heart remains heavy. Fifty years have passed, and no one has yet discovered the corpse.