Montresor is upset with Fortunato because he had laughed at his proud name and he will get revenge on Fortunato by making him know that he was paying and knew he was forcing him to pay an knew his greatest weakness was he liked to drink good wine and would drink much of it.
Montresor is angry at Fortunato's insults. We do not know Montresor invites Fortunato to his palace to try Amontillado luring him to his death.
Fortunato has drank a lot of wine. When Montresor leads him into his cellar deep in the ground. Montresor asks several times if Fortunato would like to return. He is too excited for the Amontillado
Montresor led Fortunato into the cellar door and as they went in, against three of the walls there were piles of bones higher than their heads. From the fourth wall someone had went and pulled the bones and they were spread around on the ground. And in the middle of the wall was an opening into another vault which lead to a room that was about three feet wide and was six or seven feet high. Montresor then shut Fortunato in the room.
Montresor then told Fortunato that he must deal with the consequences of him insulting Montresor. He asked him once to please not return back and if he was to refuse to do so then Montresor said he must leave Fortunato. As he spoke those words he began searching among the bones . He then found the stones he had taken down from the wall earlier.
Montresor then began quickly building the wall again, covering the hole. Fortunato then questioned what Montresor was doing but that did not stop Montresor. Fortunato then thought Montresor was pulling a joke and told him he needed to quit or else they both would be late for the Amontillado. Montresor then finished building the wall and then put all of the old bones again in a pile against the wall and said, "May he rest in peace!"