Theme Analysis in The Cask of Amontillado

In The Cask of Amontillado, Edgar Allen Poe uses imagery, symbol, and tone to prove that we humans, desire revenge. In the beginning, we knew something bad would come because Montresor wore a black mask and a black coat where as it was carnival season and everyone dressed colorfully. The theme of this story is that we get so caught up with wanting to get revenge with another person, that it takes over. Even though it's not technically natural, it kind of is. Like in the story, the guy wanted to kill Fortunato just because Fortunato insulted him, and what was his first reaction? To get back at him. He's almost like the picture on his family's arm, A snake biting the heel of the person who stepped on it.