During a carnival our narrarator, Montresor, runs into a person who has gravely insulted him, Fortunato. (who is also very intoxicated) So he seeks revenge.
Fortunato had disrespected and insulted Montresor, because of this wants revenge on Fortunato in a deadly way.
Fortunato is a expert in fine wines, this is why Montresor explains to Fortunato that he bought a bottle of amontillado without his opinion by mistake. Montresor tells Fortunato that this wine is deep within the catacombs and that he must follow Montresor to taste it.
When they finally arrived at the spot that Montresor said the wine would be Fortunato was suprised to not see any there. But in his bewilderment Montresor threw him into the niche that was in the wall and shackeled him in. Next thing you know, Montresor pulls out a trowel and starts to fill it.
Montresor is repetitivly taunting Fortunato as he fills the niche. As Fortunato whines and stuggles to escape, Montesor starts to feel regret for what he is doing and thinks that it is not to late to turn back and explain to Fortunato that this was all one big prank. But thats when Fortunato stops moving and making noise, he's dead. Montresor hurries and finishes his labor quickly.
For Half a centrury, Fortunato's remains went undiscoverd until Montresor admits to the crime recivint full impunity.