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 gives these conditions for successful vengeance at the very beginning of the story as he explains that he must get revenge on Fortunato. However, by the end, it’s entirely unclear whether Montresor’s revenge has been successful by his own definition. Fortunato is forever entombed within the Montresor vault, symbolically a part of the family history. In addition, at the end, Fortunato does not appear to understand why Montresor is locking him within the vault. However, if Montresor realizes that he has not satisfied his own conditions, he does not say so.

Nemo me impune lacessit.

This quotation is the Montresor family motto, which Fortunato asks him for as they travel farther into the vaults. In Latin, this sentence means “No one insults me with impunity,” a fitting motto for our narrator Montresor. We never learn what insult merited such a harsh revenge, and it’s in fact unclear whether Montresor even remembers which insult. To Montresor, what matters is that the perceived wrong is avenged. Montresor treats revenge as a duty bestowed upon him by his ancient family.