Background: During a time when the Spanish Inquisition was taking place, prisoners were being tormented. Poe's narrator is undergoing torture by the Spanish inquisitors.
In "The Pit and the Pendulum," there seems to be one climax after another. The prisoner is in a dungeon. There is a pit at its center. He nearly falls into the pit. Then, as the rats pervade the apartment or dungeon, the smell of the spicy meat attracting them, the prisoner develops an idea to prevent his death from the slowly, lowering, swinging pendulum.
While the reader eagerly anticipates what the prisoner's idea of escape is, the tension or rising action grows. With the pendulum upon him, the prisoner smears the meat on the ropes that bind him, and his ingenious idea liberates his very soul and physical being. While this would appear to be the climax--this moment of scarce escape--the metal walls of the dungeon begin to heat like a fire, forcing the prisoner to the edge of the pit.
The prisoner contemplates putting his body to the walls to burn himself alive. Anything but the pit would be a welcomed death. The prisoner comments that he would rather die in any way other than the pit:
I could have clasped the red walls to my bosom as a garment of eternal peace. "Death," I said, "any death but that of the pit!" Fool! might I have not known that into the pit it was the object of the burning iron to urge me? Could I resist its glow? or, if even that, could I withstand its pressure.
Again the action is rising. Will the prisoner burn himself alive or will he descend to the hell of the abyss? At this very moment, with only and inch of floor beneath him, the prisoner is falling toward the abyss, the hellish pit. The story is at its highest point of interest, the climax, when General Lasalle comes to his rescue and grabs the prisoner as he is falling:
An outstretched arm caught my own as I fell, fainting, into the abyss. It was that of General Lasalle. The French army had entered Toledo. The Inquisition was in the hands of its enemies.
The falling action begins as the prisoner is saved from his torment, from his horrible death. He escaped the pit and the pendulum.