Montresor is talking to Fortunado, who is at a carnival. Montresor has spent the time before talking to Fortunado, determining how he's going to exact revenge on him.
Montresor dons a mask before going into the catacombs. Fortunado is drunk, and not really aware as to what is going on, but heard Montresor mention Amontillado, and is following him in order to try some. Fortunado is an alcoholic, and loves alcohol.
Montresor locks Fortunado to the wall of the catacombs with chains. Fortunado is still very drunk and asks Montresor if the joke is over, and that they can go back, but he passes away seconds later. Montresor then puts the bones back and leaves.