As Poe repeatedly maintained in his critical views, the most successful story occurs when the author decides what effect or effects he wants to achieve and then decides what techniques to use to achieve that effect. In "The Pit and the Pendulum," Poe apparently had in mind the effects of unrelieved torture and suspense.
The story begins with the trial of the narrator, as he sits before seven very severe judges; he is "sick — sick unto death," because the judges have an "immoveable resolution — of stern contempt of human torture." The narrator is so completely obsessed by the horror of the proceedings that he cannot even hear his sentence as it is being pronounced; instead, he recalls all of the horrible tales of "monkish tortures" which awaited the victims of the Inquisition. After swooning, the narrator awakens in total darkness; before opening his eyes, he imagines the horrors that await him. At last, his worse fears are confirmed: "The blackness of eternal night encompassed me." At first, he wonders if he is dead yet still mentally conscious. This concept often appears in Poe's fiction — that is, a person will be physically dead, but he will still retain the mental ability to know things after the death of the physical body.
After many moments of suspense, he investigates his situation. He knows that he is condemned to death; but the method and the time for his execution are unknown to him. Since he has heard so much about the horrors of the dungeons, he is certain that he is in one of those dungeons. After feeling around, he determines that it is in the shape of a vault. The floors are covered with slime, but carefully feeling his way around, he calculates that the vault is about fifty feet wide. He then begins to traverse the vault, but he slips on the slimy floor and falls. His body hits the floor and he discovers that his head lies on the perimeter of a seemingly bottomless, circular pit. A few steps more and he would have fallen to a horrible death.
Arousing from a sleep, he finds by his side a loaf of bread and a pitcher of water. After drinking deeply, he realizes that the water must have been drugged since he immediately loses consciousness again, and later, when he is again awake, there is a sulfurous light which reveals that the walls are one-half their original size. Logically, he tries to determine how he originally made such an error. He knows that he is in the same place because of the horrible, dismal circular pit. But to his horror, he is now completely bound head and foot, except for his left hand up to his left elbow. He is bound to a "species of low framework of wood." Looking upward, he sees a huge razor-sharp pendulum swinging in an arch, criss-crossing his body. Turning to survey the rest of the vault, he sees enormous rats running across the slimy floor. After watching the rats for about thirty minutes, he again looks at the pendulum and is horrified to realize that the sweep has increased considerably and even more disturbing, it has descended. Now he "can no longer doubt the doom prepared for [him] by monkish ingenuity in torture." The sweep of "the pendulum was at right angles [and] was designed to cross the region of the heart." The vault and the bottomless pit are just as horrible as the very pit of hell itself might be. It seems as though it is days before the pendulum comes so close to him that the "odor of the sharp steel forced itself into my nostrils," but eventually it does, and when the pendulum vibrates within only three inches of his breast, he calmly reasons that the pendulum will cut his bandages before it will cut him. With all of "the keen, collected calmness of despair," he conceives of a plan. Using his left hand, he takes what spicy food he is able to rescue from the rats and smears it all over the bandages that bind him. The rats then throng all over his body ravenously gnawing at the bandages. The narrator, while almost succumbing to disgust, is at last able to free himself — just as the pendulum is about to cut through his clothes.
Even though he is free, however, one horror follows another. The pendulum is immediately withdrawn, thus making it apparent that his every action has been observed. Almost immediately, the dungeon becomes hotter, and he notices that the walls are not attached to the floor. It gradually becomes hotter and hotter, until the engraved faces of the fiends on the wall begin to glow. As the heat rapidly increases, the walls begin to close in upon him. For a moment, he considers jumping into the pit to escape the burning metal closing in on him. '''Death,' I said, 'Any death but that of the pit. Fool! Might I not have known that into the pit was the object of the burning iron to urge me?'"
As the walls are closing in on him, he realizes that he is being forced toward the very edge of the horrible pit. His "seared and writhing body" can stand it no more and as he lets out a piercing scream, suddenly there is a blast of trumpets and the walls roll back. The narrator is rescued, and the torture of the Inquisition is over.
As is often the case in Poe's stories, the first-person narrator is not named, and he is about to be punished for an unknown crime. But unlike many of Poe's stories, we do know the time and place of this story: It takes place in Toledo, Spain, during the Spanish Inquisition. Of course, this setting and time is so far removed from the present day that the story does conform to the Romantic tradition of placing stories in some distant place and time so that there are no real identifications made. Again, Poe's story has (1) an unnamed narrator, (2) is set in the distant past, (3) concentrates upon a single effect — the effect of terror or horror by means of mental suspense, and (4) is related to many other stories by Poe's concept that in sleeping, in fainting, and, ultimately, even after death, there is a "something" that still lives and is still active, some part of the human essence ("even in the grave all is not lost" is a main idea of Poe's "Ligeia," "The Fall of the House of Usher," "The Premature Burial," and other stories).
The most unexpected aspect of the story is that it has a "happy ending"; the narrator is saved. In terms of realistic fiction, this sudden, unprepared-for rescue would be condemned as artificial or as being forced and contrived. However, the essence of Romantic fiction is the unexpected, the bizarre, and the unusual (see "Poe and Romanticism").
Furthermore, in spite of the emphasis of this story being on the unrelieved mental torture inflicted upon the narrator, who is related mentally to many of the over-sensitive heroes of the other stories (he often faints and loses control), the narrator is also akin to M. Dupin (the rationalist), in view of the fact that at the crucial moment between life and death, he gathers his mental powers together, and by putting them to use in a calm rational manner, he is able to effect his release from certain death by the pendulum.
In this story, Poe has shown himself to be a master of achieving the effect of mental torture and horror as the narrator is offered a horrible choice of death: He can plunge to death in a bottomless pit of unknown horrors filled with ravenous rats, or he can wait and be sliced up by the razor-sharp pendulum — or he can wait to be crushed by the burning hot walls closing in on him, or, finally, he can jump into the horrible pit.