Like his character, Montresor, author Edgar Allan Poe pays close attention to detail, and it is a factor that greatly enhances the mood of "The Cask for Amontillado." The grim nature of the catacombs is one example. It is a dark and cold place that proceeds downward in a seemingly endless manner. This setting particularly creates a mood of danger and death.
I took from their sconces two flambeaux, and giving one to Fortunato, bowed him through several suites of rooms to the archway that led into the vaults. I passed down a long and winding staircase, requesting him to be cautious as he followed. We came at length to the foot of the descent, and stood together upon the damp ground of the catacombs of the Montresors...
We had passed through long walls of piled skeletons, with casks and puncheons intermingling, into the inmost recesses of the catacombs.
The clothing worn by Fortunato creates an ironic twist to the story. Not only are Fortunato's actions in following Montresor into such a place foolish, but so is his dress: It is his carnival costume, that of a court jester.
The man wore motley. He had on a tight-fitting parti-striped dress, and his head was surmounted by the conical cap and bells. I was so pleased to see him that I thought I should never have done wringing his hand.
The details that describe Montresor's final act, of entombing his enemy, are vivid and precise, showing the killer's careful planning and the awful final moments of Fortunato's last contact with a living human.
As I said these words I busied myself among the pile of bones of which I have before spoken. Throwing them aside, I soon uncovered a quantity of building stone and mortar. With these materials and with the aid of my trowel, I began vigorously to wall up the entrance of the niche...
I laid the second tier, and the third, and the fourth; and then I heard the furious vibrations of the chain. The noise lasted for several minutes, during which, that I might hearken to it with the more satisfaction, I ceased my labours and sat down upon the bones. When at last the clanking subsided, I resumed the trowel, and finished without interruption the fifth, the sixth, and the seventh tier. The wall was now nearly upon a level with my breast.