During Carnival, Montressor runs into Fortunato, and offers a nice bottle of Amontillado wine with him. However, this bottle is in his catacombs, and Fortunato is drunk.
Montressor claims that Fortunato has gravely insulted him, and is plotting to get revenge on him. The narrator does not make it clear what Fortunato has done to him, but makes it clear that it is unforgivable.
Montressor leads Fortunato into the dark and eerie catacombs. As they continue, Montressor repeatedly asks Fortunato if he would like to turn back because he seems ill. Fortunato continues to drink wine to ease his cough.
When they reach the is destination, there is no wine. Just a crypt filled with bones and an empty tomb. Montressor chains Fortunato inside the tomb and begins to build levels of stone and mortar.
As he lays the last few bricks, Fortunato screams for Montressor to stop. Though, it is too late. Montressor has already taken on his revenge.
For the love of God, Montressor!
Montressor heard nothing but Fortunato's jingling of bells as he walked away. In the end, he says that no one has disturbed the tomb for 50 years.