The narrator is receiving a sentence of death because he did not reveal his crimes. Before he passes out he sees two black robed people.
The narrator finds himself in and out of consciousness and finds himself in a chamber of some sort, but suspects its related to some sort of punishment
The narrator tries to explore his chamber but almost slips into a chasm at one end of it. When awoken, the narrator finds water and bread.
The narrator finds himself strapped to a table with only his left arm free. As he looks at the ceiling he sees a figure holding a pendulum, but it is a razor sharp blade. He realizes it will soon kill him.
As the narrator realizes he will soon die, he gets an idea to rub meat on his straps so that the rats would gnaw on the straps freeing him. As soon as he was free, the walls started to become hot and had started moving, forcing him to move toward the chasm.
Just as the narrator is about to die, he hears thundering trumpets, the walls go back, and he is saved by General Lasalle, who was leading the french troops into Toledo.