Before the story begins, we are presented with an epigraph in Latin which translates as follows:

Here an unholy mob of torturers with an insatiable thirst for innocent blood, once fed their long frenzy. Now our homeland is safe, the funereal cave destroyed, and life and health appear where dreadful death once was.

By beginning with some lines in Latin, the meaning is slightly less accessible and begins the story with added mystery. This is compounded by the note that follows:

Quatrain composed for the gates of a market to be erected upon the site of the Jacobin Club House at Paris.

Who were these Jacobins? This group took control of France in the early 1790s, growing more and more radical as time passed. Eventually, they just began beheading via guillotine anyone who disagreed with them. This became known as the "Reign of Terror" in France.

This epigraph furthers the mood that Poe is crafting, one that is dark, fearsome, and horror-laden. It is also a reminder that the Spanish Inquisition was not the only historical faction to employ torture and death to eliminate their adversaries. Thus, Poe crafts a narrative that speaks to the "Reign of Terror" of mankind's entire history.

The narrator of this story finds himself on the wrong side of the dominant faction, which has been the case for many people throughout history. His torture, then, speaks to the historical torture of mankind, as is alluded to through the Jacobins and the Spanish Inquisition in this story. As we enter the mind of the narrator in the next lines, we are immediately propelled into the mood created by knowledge of historical tortures and massacres.

Preceding the initiation of the story's plot, there exists an epigraph that is described, in parentheses, as a set of four lines composed to adorn the gates to a market that was built in Paris at the site of the Jacobin Club House. The Jacobins were responsible for a number of massacres and executions during the Reign of Terror during the French Revolutions. These lines describe the Jacobins as an "impious mob of torturers" who preyed on innocents and spilled their blood. With the Terror over, the lines say, this "cave of murder" is razed, and "life and health" are made available to all (as the spot becomes a market where fresh foods and sundry goods are sold).

These lines, assuming one can understand the Latin, would help to create dramatic tension—even before the story itself begins—because it must make us wonder which "impious ... torturers" it is meant to describe: it is a clue that the story will contain just such a ruthless and brutal mob of villains who victimize innocents. Who will be guilty? Who will be killed? The epigraph is a hint that this story will contain torture and murder, such as the type of which the Jacobins were guilty. This creates certain expectations within the reader, and our tension rises as we await whatever brutality follows.

The narrator gives the impression, at the opening, of waking from a nightmare—but it's actually a new nightmare that is beginning for him. The robed figures surrounding him are Inquisition judges who have just pronounced his death sentence. What's unusual, perhaps even for Poe, is the way the reader is thrown off balance by this particular in medias res start, in which it's difficult to reconstruct what has already happened despite the vividness of description:

I was sick—sick unto death with that long agony . . .

With "that long agony"? What could he be alluding to? Only a prior knowledge of the Inquisition and its methods would enable us to grasp that he has already been tortured. The effect is slightly ironic that he is being unbound, and the reader must wonder, for what purpose now? We know that he's to be killed, so why are they unbinding him? This mystery, in the context of dreamlike imagery in which the robed figures appear like ghosts with their exaggeratedly white lips and the "indeterminate hum" of their voices, prepares us for the terror which will follow—but exactly what it will be the reader can only guess.

As is not unusual for Poe, the narrator describes his own literal act of writing the story on a white sheet of paper still not as white as the lips of his torturers. Does this tell us that he will actually survive the death sentence (as he will)? Not necessarily, since in another of Poe's most famous stories, "The Black Cat," the speaker is similarly writing his "confession" though his execution is imminent. Poe gives us this information as a tease. It enhances the feeling of mystery and strangeness in the bizarre opening in which, as usual, the line between reality and dream is so artfully blurred.

In the first lines of "The Pit and the Pendulum," we are thrust into the middle of the dramatic story of the unnamed narrator. We learn that a death sentence had been passed on him, though we don't know why, and that he seems to have been granted a reprieve at the last moment. He is in a dizzy, dreamlike state, perhaps on the verge of fainting--"I felt my senses were leaving me," he writes. We learn too that he is in the hands of "inquisitorial voices," perhaps suggesting we are back in the days of the Spanish Inquisition, although "inquisitorial voices" can exist in any era. Finally, in his dizzy, dreamlike state, the narrator feels a sense of something revolving, such as mill wheel, a foreshadowing of what is to come. 

This beginning creates dramatic tension in several ways: By starting off in the middle of the action, or media res, at what appears to be a climax of the story, the reader is immediately hit with the emotional intensity of the scene and pulled into narrative, curious to know what has and will happen. Second this opening is in first person, which encourages us to identify with the narrator. We are witness to his emotions and his sense of disorientation. This heightens the drama, for we feel what he feels, see what he sees. Like him, we find ourselves groping for answers. Finally, with its talk of death and inquisitions and its uncanny, off-kilter quality of waking from a nightmare that may not be over, it creates an immediate sense of unease and foreboding.