No matter how hard he tries to use his mental faculties to assess his situation and avoid his tortures, the narrator is outmaneuvered by his tormentors and reduced to a state of near madness. At first terrified of being prematurely buried, the narrator is frustrated in his attempts to explore his prison. His terror increases as the threat of the pit gives way to that of the pendulum, to the point that he becomes nearly mentally unhinged. He finally manages to affect an escape from the pendulum, only to be confronted with another inescapable terror.
These are shadowy figures the narrator doesn't clearly see, but who carry him into his prison, give him food and drink, and prepare his torture.
At the beginning of the story, the black-robed judges, who are officials of the Inquisition, pronounce the narrator's sentence of death.
LaSalle is the Napoleonic general who rushes in to rescue the narrator just as he is about to fall into the pit at the end of the story.