on charges of murder.  To be so charged would negate the value of the act in his eyes.  However, Montresor never seems to consider that, though he may succeed in maintaining the appearance of innocence, he may still feel guilty about his crime, and this guilt could be punishment enough to "overtake" him as the redresser he discusses.

When Montresor speaks, we can see that he is speaking to someone.  He says, "You, who so well know the nature of my soul, will not supposed, however, that I gave utterance to a threat."  Who is this "You"?  Who would "know the nature" of Montresor's soul?  Some would argue that he is speaking to a priest as a priest would, theoretically, have this knowledge.  Further, in the story's conclusion, Montresor says, "For the half of a century no mortal has disturbed [Fortunato's bones]."  Therefore, it has been some fifty years since he took his revenge on this enemy.  It is reasonable to suggest that Montresor is now an old man, perhaps on his deathbed, and that he is making his final confession to a priest before his death.  The final line of the story ("In pace requiescat!"), which translates to "rest in peace," could be applied, then, to either Fortunato or to Montresor.  Perhaps Montresor felt that he could not rest in peace with this sin still on his conscience, and so he had to confess it.  This would mean that his conscience has been weighted with his guilt for the past fifty years, and, if this is the case, has he really gotten away with his revenge?  Wouldn't his guilt be a terrible punishment?  

Therefore, a potential thesis could read: Although Montresor believes that his revenge on Fortunato was successful because he escaped punishment for his crime, ultimately, his own guilt punishes him for what he did, and this negates the achievement of his revenge.

Because the story is entirely about revenge, a thesis statement could cover any number of possible topics, from potential consequences to the debate over exactly what "injury" Fortunato enacted on Montresor. One good theme is the correlation between pure revenge and Montresor's warped sense of morality and justice. Montresor explicitly states that his revenge is both justified and should not be considered a crime, even though he understands that it will be a criminal act.

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. A wrong is unredressed when retribution overtakes its redresser.(Poe, "The Cask of Amontillado," croads.virginia.edu)

Despite this, he goes through with his plan without a second thought. Montresor therefore thinks of justice as a moral balance, with "sides" between people capable of being tipped to one side or another. Since he assumes that no other will avenge him, he must take revenge without having another "injury" (such as imprisonment) done to him in turn.

An example of a thesis using these themes would be: "Montresor's revenge is, in his mind, entirely moral according to his ideas of personal honor, but he still understands that his act would be seen as wrong in the public eye."

The narrator and main character is a pre-meditated murderer. This is the basis for “The Cask of Amontillado,” by Edgar Allan Poe.  Montresor lures Fortunato to his death.  The why and how are the essence of the story.

Revenge motivates Montresor and the story. Fortunato and Montresor have an odd relationship.  Apparently, Fortunato says things without thinking, and his hubris does not allow him to realize that someone might take offense at what he says. 

Montresor appears to be telling his story to someone who has more knowledge of his character than the reader ‘‘You, who so well know the nature of my soul.” Montresor has pledged to take his vengeance because Fortunato has insulted him.  He further states that Fortunato has injured him a thousand times but gives no details about those injuries.

The thousand injuries of Fortunato I had borne as I best could, but when he ventured upon insult I vowed revenge.

It is the insult that takes him over the edge.

Apparently, Montresor’s family has never taken an affront lightly.  Even their family motto indicates that they punish those who attack them and without being punished themselves [impunity]. Further the coat of arms displays a snake being crushed by a foot but the snake gets its revenge by turning and biting the foot in the heel.

 'I forget your arms.'

'A huge human foot d'or, in a field azure; the foot crushes a serpent rampant whose fangs are imbedded in the heel.'

'And the motto?'

'Nemo me impune lacessit.' [No one wounds me with impunity.]

For Montresor to revenge himself for Fortunato’s insult, he has to get away with it – if Fortunato can revenge pay him back then his efforts will have been useless. The punishment must be permanent − Fortunato has to feel it, and he has to know it is coming from Montresor.

Montresor devises and plans in detail how to seek his revenge from Fortunato by luring him into a place where no one will be able to hear, see, or discover him.  To have his victim know that he is going to die and realize that it is because of a ridiculous cask of wine will give great pleasure to Montresor.

.. . 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.

Montresor will get his revenge and not be punished.  The reader knows that this is true because the entire story is a flashback told by the elderly Montresor fifty years later, and Fortunato's bones have never been disturbed. 

Throughout the short story Montresor excitedly and with a since of eerie pride outlines to his audience how he planned and carried out his revenge of Fortunato for an unnamed crime he has carried out against the narrator.  The first line of the story introduces to us that this is no ordinary murder or accidental death.  Instead, Montresor sets the theme of this story to be the revenge he seeks when he explains his vow of revenge against Fortunato. 

The thousand injuries of Fortunato I had borne as I best could, but when he ventured upon insult, I vowed revenge.

Revenge takes planning and careful patience, so Montresor waits until the time of the carnival when he can lure the drunken Fortunato into the crypts under the guise of examining a cask of amontillado.