After Montresor explains that he is going to get revenge on Fortunato, the story starts at the carnival. Montresor comes upon Fortunato at dusk, and it's obvious that Fortunato had been drinking a lot. Fortunato is dressed similar to a 'royal fool' from the medieval times. Montresor tells him that he "... received a pipe of what passes for Amontillado, and I have my doubts" (Poe, 7), which gets Fortunato to believe that he bought the very expensive wine.
While beginning the descent into the catacombs, Montresor notices Fortunato's cough. This is caused partially from the Nitre on the wall and Fortunato's excessive drinking. Montresor tries to tell him that they should go back, but Fortunato claims that he "... shall not die of a cough" (Poe, 36), and keeps walking. However, this was just a reverse psychology trick by Montresor, to make Fortunato keep going further into the tunnel.
In a portion of the deep catacombs, Montresor chains Fortunato to one of the walls to were he is stuck. He locked the chains with a pad lock and told Fortunato that he has to leave him behind. He explained that there was too much nitrate for him to continue with his cough. Then, Montresor discovers a mortar and stones to build with.
In pace requiescat!
After building almost all of the brick wall, Montresor has one final chat with Fortunato. Fortunato thinks Montresor is just joking and starts laughing. After a few more random comments from Fortunato, he stops responding. Montressor explains, "But to these words I hearkened in vain for a reply. I grew impatient" (Poe, 85), then calls for Fortunato, with no response.
Fortunato was unable to talk, so he jingled his bells in response to Montresor. Montresor narrates, "My heart grew sick; it was the dampness of the catacombs that made it so" (Poe, 89). Montresor still feels bad for what he did to Fortunato, but brushes it off as the dampness of the catacombs. He doesn't want to admit that he actually feels remorse for what he did to Fortunato. Next, he put the last stone into place and left the catacombs.
After trapping and killing Fortunato, Montresor kept his story a secret. Still, fifty years later, no one had found the body of Fortunato. According to Montresor's testimony, "For the half of a century no mortal has disturbed them [the rampart bones of the catacombs]" (Poe, 89). No one knows for sure who the story was intended for. Most people assume he was telling it to his family, or just to anyone reading it.