How does Montresor kill Fortundo in "The Cask of Amontillado"?
Montresor wants to kill a man but naturally doesn't want to be exposed and punished for murder and doesn't even want to be a suspect. He decides that the only way to commit a murder with impunity would be to make the victim disappear without a trace. The chains attached to the granite wall of the catacombs under his palazzo have probably been there for centuries. Montresor must have discovered them while exploring the catacombs by torchlight. No doubt the chains had been used by feudal lords to execute rebellious subjects. Montresor realized that he could murder Fortunato in the same way if he could get him underground without being seen in his company on the night of his disappearance. This inspired Montresor to invent the cask of imaginary Amontillado. It wasn't sufficient to invite Fortunato to come to his palazzo to sample it as a favor to a friend. Montresor embellished his falsehood with the statement that he had bought a big amount at a bargain price. Both Fortunato and Montresor refer to the cask as a "pipe," which is a wine-barrel containing 126 gallons. Fortunato does not seem like a sherry drinker. Sherry is a sipping wine, and Fortunato is characterized as a glutton and a guzzler. Fortunato is interested in the "bargain" aspect of the purchase. The fact that he refrains from asking Montresor where he bought it and how much he paid for it suggests that Fortunato is planning to sample the wine and judge it to be ordinary sherry. Montresor is in a big hurry to get an opinion on his Amontillado that night, either from Fortunato or from Luchesi. This suggests that Montresor plans to buy more if he can be assured that it is genuine. Montresor is a poor man, as he himself acknowledges. He is not the kind of man who would want 126 gallons of sherry for personal consumption, and he certainly would not want to buy additional casks for that purpose. Fortunato--as Montresor knows and expected--would put Montresor off by disparaging the wine and then rush off to find the cargo, apparently newly arrived by ship from Barcelona, and buy it all up for himself. An excellent jest! This is probably an example of the kinds of injuries that have made Montresor decide to kill him. So Montresor uses Fortunato's greed and duplicity to lure him into the catacombs and chain him to the granite wall. The fact that his murder plot was completely successful is shown in the last words of the tale:
Fortunato has turned into a skeleton dressed in the rags of a jester's costume. Montresor no longer has any reason to hate him. When he concludes with "In pace requiescat" ("Rest in peace") he means it sincerely. He has been thoroughly cleansed of his hatred and can now feel pity for his victim
Montresor walls up Fortunado in the catacombs under the city by sticking him in a crevice and bricking him in.
Montresor is upset because of some perceived injury Fortunado has done him. He tricks him by saying he needs him to look at a rare cask of wine in the catacombs, tunnels under the city. Then he brings him deeper and deeper, and since the man is drunk he is not aware of what is happening until it is too late.
…I busied myself among the pile of bones of which I have before spoken. Throwing them aside, I soon uncovered a quantity of building stone and mortar. With these materials and with the aid of my trowel, I began vigorously to wall up the entrance of the niche.
Fortunado screams, but they are deep below the city and no one can hear him. Montresor has plenty of time to wall him in, and eventually he will suffocate to death and no one will ever know what happened to him or suspect Montresor. Montresor comments that it is important that he commit his act of revenge without getting caught. This is why it is important to commit the perfect crime.
He takes fortunado to the catacombes when hes drunk and walls him alive basically masoning him into the walls of the catacomb after tying him to the walls of the catacomb.