Edgar Allan Poe's magnificently constructed, but disturbing, tale contains a perplexing mixture of elements that generate the suspense as well as the terror. Oddly enough, from the beginning of the story, the reader is aware of Montresor's revenge since in the frame story he informs his readers that he has "punish[ed] with impunity" his enemy who has wronged him through "a thousand injuries." This is repeated when he says that, after making his revenge plan, he continued to "smile in" Fortunato's face, as was his custom, but that his "smile was now at the thought of his" sacrificial burial, a sacrifice to the wrongs done by him to Montresor. Yet the suspense mounts until it terminates in a horror for which the reader has not been prepared.
Here are some of the devices that Poe utilizes to create and heighten the suspense in "The Cask of Amontillado":
In his introduction to the tale of his revenge, Montresor contends that he has suffered a "thousand injuries," but fails to clarify this claim. He also states that the punisher must not be caught and he must let his victim become aware that he is avenging himself. These statements in the frame story generate curiosity in the reader as to how revenge has been accomplished. Then, as one critic has remarked, Poe creates a "red herring" with the cask of Amontillado as the lure to get Fortunato into the catacombs.
In addition, with his narrator, Poe employs the technique that he called arabesque, a fancifully combined pattern of returning to the initial disturbing idea. That is, Montresor feigns concern for Fortunato's health repeatedly, saying that they should turn back, the niter is bad for Fortunato, etc. all the time luring Fortunato deeper and deeper into the labyrinth of the catacombs, which become increasingly narrower and more covered with niter.
Poe's use of sexually connotative language is also disturbing. The bones that "lay promiscuously upon the earth" are in the path of the area where Fortunato "endeavored to pry into the depth of the recess." In a way, Montresor seduces Fortunato into the deep recess by means of his jesting with the trowel and playing upon the word mason. Then, when Fortunato finds his progress "arrested by the rock," he is bewildered. Montresor narrates,
"The Amontillado!" ejaculated my friend, not yet recovered from his astonishment.
When a series of screams are uttered from Fortunato, Montresor narrates,
Unsheathing my rapier, I began to grope with it about the recess...I placed my hand upon the solid fabric of the catacombs, and felt satisfied....
When it is midnight, Montresor places the last stone in position when there is emitted a low laugh from within "that erected the hairs upon my head." Stunned, then, Montesor says that he barely recognizes the voice as "that of the noble Fortunato."
Poe creates suspense with the introduction of the symbolic coat of arms and the trowel, which Montresor makes a pun with Fortunato on his being a Mason. [Freemasons vs. brick mason]
Certainly, the catacombs that are underground, with their maze of rooms that narrow with each turn, where bones
had been thrown down, and lay promiscuously upon the earth, forming a one point a mound of some size
create suspense and horror as the reader wonders why bones have been piled up. Moreover, there is even greater wonderment and horror as Poe subverts these Gothic conventions by using human beings, rather than the supernatural, for the terrible deeds. Montresor screams himself at the end of the tale of his revenge. For, the real terror is in the capacity for horror that the human mind possesses. Moreover, the motive for the murder of Fortunato is never revealed, indicating the disturbing madness of the narrator; he is the most grotesque of all the elements of the story in his sensually-charged murder, motivated solely by what has been in his mind.