The story takes place in 17th century Italy during carnival season. The narrator and protagonist, Montresor has been injured by the antagonist, Fortunato, but once Fortunato insults him, he wants revenge. Montresor's plan for revenge also includes not getting caught.
"Once more let me implore you to return."
Montresor, dressed in a costume symbolic of the grim reaper, sees Fortunato at the carnival. Fortunato is a wine expert, he is also drunk and has a cough. Montresor, knowing this, tricks Fortunato into following him to taste expensive wine. Montresor does this by flattering him and pretending he doesn't want Fortunato to come.
Montresor leads Fortunato into the catacombs, symbolizing how he leads him to his death. He gives Fortunato wine to keep him drunk and toasts to his "long life," this is ironic because Fortunato dies after this. Montresor says that his coat of arms is a snake biting a giant crushing foot, symbolizing how Montresor will punish Fortunato for insulting him. He also tells Fortunato that he is a mason, and pulls out a trowel, foreshadowing that he will use it later.
"Rest in peace!"
Montresor and Fortunato reach a dead end in the catacombs and Montresor corners Fortunato in a niche. Fortunato is too drunk to realize what is happening when Montresor chains him to the wall. Once he is chained, Montresor uncovers a pile of bricks and starts to build a wall around him.
After he sobers up, Fortunato screams and fidgets in the chains, and Montresor screams back. Before he places the last brick, Montresor gets a good look and Fortunato, who tries to play it off as a joke. Montresor calls for Fortunato before placing the final brick, and gets no response but the jingling of the bells on his hat, which is ironic because he was fooled, and dressed as a fool.
Montresor says that his heart feels damp, and says the nitre was the cause, but he really feels guilty about murdering Fortunato. In the last paragraph, Montresor reveals that no one has uncovered the corpse for 50 years. The theme of this story is that "revenge is a strong motivator." The internal conflict is Montresor feeling guilty, so it is Montresor Vs. himself.