Writting a letter to Poe. Explain whether you found the characters believable and the ending satisfying.
The characters are believable because there are plenty of people who hold a grudge like Montresor and there are sociopaths who will kill for imagined wrongs. Likewise, people do forget themselves during parties like the carnival and do things they normally would not, such as drink too much.
The characters are believable when you consider them in the context of their environment, the society and time in which they would have lived.
Montresor's behavior, his desire for revenge, his intricate plan to get back at Fortunato have a ring of truth when you consider the Italian culture. If Fortunato has insulted Montresor's family, it would be a matter of honor for him to seek revenge on him.
Montresor's need for revenge comes from a long held belief in Italian society that it was acceptable to even hire paid assasins to exact revenge on someone who has done you harm.
In the story, we know that Fortunato has insulted or harmed Montresor with many, many, unnamed offenses.
"Reference to the traditional Italian concept of revenge illuminates some of the questions that arise from a close reading of Poe's "The Cask of Amontillado." The ground rules that Montresor lays down for his revenge and the methods he employs in carrying it out coincide directly with popular ideas about the Italian code of revenge, which were formed in Elizabethan times and persisted in America in Poe's day."
The end of the story, in view of the practice of revenge, was satisfying. As Montresor walks out of the catacombs, he utters rest in peace, he is therefore honoring his ancestors, his family, by telling them that he has sought justice and restored honor to their name.
This was, and to a certain degree, still is, a big deal in Italian culture.