The Cask of Amontillado - Edgar Allan Poe

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 definitely settled-but the very definitiveness with which it was resolved, precluded the idea of risk. I must not only punish, but punish with impunity.