It was the 17th century, Italy at carnaval. Montressor has been insulted and injured by Fortunato. Due to Fortunato doing this to Montressor, Montressor vows to get revenge ( Montressor vs. Fortunato ).
Lets go back. No ok then!
No Montressor! (chains shackling and bells ringing)
While Montressor was at carnaval dressed in all black (and black usually means death) he encountered Fortunato dressed as a fool (Fortunato was made to be a fool). Since Fortunato was a wine expert Montressor took the advantage that Fortunato was sick, and drunk to get back at him. So, he tricked Fortunato by complimenting him and by lying saying that there was Amontialldo in his catacombs. Montressor also manipulated him saying that he wants no harm and he will just ask Luchressi to test the expensive wine. So, Fortunato says he will go and off they went.
Ahhhhhh!! Stop Montressor!!!
Since there is a lot of nitre in the catacombs Fortunato's cold is getting worse. As they walk through the catacombs there is wine so Montressor keeps giving Fortunato wine to make him more drunk and there first toast was to Fortunato's long life. As they get deeper into the catacombs the nitre is getting thicker so once again Montressor is manipulating Fortunato by insisting that they should go back but Fortunato says that he wont die from a cough. Finally they get to the deepest part of the catacombs.
Rest in peace
There is a niche in the in the deepest part of the catacombs. Montressor claims that the Amontiallado is in the Ninche. As Fortunato walks to go in the ninche Montressor chains Fortunato in the ninche, but Fortunato is to drunk to realize what is happening.