The first paragraph of Edgar Allan Poe's short story "The Cask of Amontillado" consists on Montresor's confession to the reader as to what he is planning on doing against his so-called friend, Fortunato. In typical Poe fashion, the main character of this story has some disturbance that has bothered him for quite some time. In this case Montresor wants to take revenge on Fortunato, who is a boisterous man that takes Montressor as his butt of jokes. At this point we do not know exactly what Fortunato has really done, but we can perceive the wrath and anger that Montressor has been nursing. Montresor also tells us that his revenge is being carefully planned, that it is a secret, and that it is official. Fortunato is going to pay for everything he ever said to Montresor.
The thousand injuries of Fortunato I had borne as I best could; but when he ventured upon insult, I vowed revenge. You, who so well know the nature of my soul, will not suppose, however, that I gave utterance to a threat. AT LENGTH I would be avenged; this was a point definitively settled -- but the very definitiveness with which it was resolved precluded the idea of risk.
He also shows the degree of energy that his anger has taken from him. Montresor is not planning a simple slap on Fortunato's wrist. His plan is big, morbid, and malicious. It is geared to make Fortunato suffer a lot. He says that a wrong is not set right when vengeance overtakes the person that is trying to make it right. Also, a wrong is not made a right when the avenger does not make his bully feel as bad as his victim. Therefore, in Montresor's opinion, the only way to make something bad into something good is to teach the person who bullies or annoys you exactly how you feel. An eye for an eye is Montresor's way of fixing the problem with Fortunato.
I must not only punish, but punish with impunity. A wrong is unredressed when retribution overtakes its redresser. It is equally unredressed when the avenger fails to make himself felt as such to him who has done the wrong.
Therefore, this first paragraph is the confession of Montresor as to what his plans will be. Never in the story do we really find out what Fortunato has done other that, whatever it is, has really bothered Montresor. Nothing could take the idea away from Montresor: Not his money, nor his palazzo, nor his good fortune. He simply wants revenge.