not move. In order to escape being slowly cut in half, he spreads what little is left of his food onto the strap holding him down and the rats chew through it, and it is just in time for him to move out of the way before the pendulum could do too much damage.

The first danger the narrator faces is being in an unfamiliar room in the dark. He makes his way around the room and finds there is a pit into which he could fall. The second danger he finds is the bread, which he devours and then realizes has been laced with some sort of drug or poison.

When he wakes up, he is tied to a bed or platform of sorts and the razor-sharp pendulum is descending upon him. He takes the salty meat that was left for him (no water) and smears it across his ropes. The rats that live down in the pit smell the meat and then chew the ropes, which frees the narrator.

After his trial, the narrator firstfinds himself imprisoned in total darkness inside a small cell. "The blackness of eternal night encompassed me." Being confined is, itself, frightening for the narrator--"[T]he atmosphere was intolerably close,"-- but his terror is increased when, having moved along the damp walls in order to determine the size of his cell, the narrator secondlydiscovers that there is a hole in the floor. 

After the narrator trips over a remnant of cloth that he has used to mark the beginning of his walk around his cell, he discovers a startling circumstance: While his chin lies on the floor of the cell, his

...lips, and the upper portion of my head, although seemingly at a less elevation than the chin, touched nothing.

At the same time, the prisoner feels a "clammy vapor" on his forehead and he smells "decayed fungus." When he puts out his arm, he discovers that he has fallen at the very edge of a circular pit. Breaking off a small fragment of masonry just below the margin of the hole, the prisoner drops it into the pit only to realize that it is a deep pit filled with water. When there is a rapid opening and closing of an overhead door, the narrator "saw clearly the doom which had been prepared for me." He congratulates himself on escaping this deadly accident by his timely fall.

The first two dangers faced by the narrator of this story would be the pit and the pendulum, so the story is aptly named.

When he first wakes up in his pitch black cell, he starts trying to measure its size by trailing his hands along the wall and measuring by pace. This in and of itself is not the dangerous part; it is when the narrator paces more into the center of the room, trying to figure things out, that he comes close to losing his life. He trips and falls, and he realizes that his head is not touching anything, meaning that he tripped close enough to the pit that his head dangled over the edge.

The next danger is after he is drugged by his food and he wakes up tied down to the floor, and he can see the pendulum slowly descending as it swings back and forth. Luckily, he is clever, and he spreads what is left of his food onto the ropes holding him down, which baits the rats into chewing through the ropes and setting him free just before the pendulum reaches him.

Poe's short story "The Pit and the Pendulum" begins with a rather ambiguous account of the narrator being sentenced to some form of punishment and losing consciousness.  Upon first regaining consciousness, the first problem he encounters is that he does not know where he is:

I felt that I lay upon my back, unbound. I reached out my hand, and it fell heavily upon something damp and hard. There I suffered it to remain for many minutes, while I strove to imagine where and what I could be. I longed, yet dared not to employ my vision. I dreaded the first glance at objects around me. It was not that I feared to look upon things horrible, but that I grew aghast lest there should be nothing to see. At length, with a wild desperation at heart, I quickly unclosed my eyes. My worst thoughts, then, were confirmed. The blackness of eternal night encompassed me.

From this exposition, we see that his senses are unable to tell him where he is.  Other than touching something "damp and hard" and seeing--if you can call it that--"the blackness of eternal night," he doesn't have any sense data from which to determine where he has been put for his punishment.

After groping around in the dark to deduce where he is and what his surroundings consist of, the narrator encounters his second problem: that there is a large pit in the center of the dungeon into which he has been thrown:

I put forward my arm, and shuddered to find that I had fallen at the very brink of a circular pit, whose extent, of course, I had no means of ascertaining at the moment. Groping about the masonry just below the margin, I succeeded in dislodging a small fragment, and let it fall into the abyss. For many seconds I hearkened to its reverberations as it dashed against the sides of the chasm in its descent; at length there was a sullen plunge into water, succeeded by loud echoes.

As with his deduction that he was, in fact, in a dungeon in the first passage, this quotation shows the narrator using reasoning, dropping the "small fragment" into the "abyss" and listening for it landing, to ascertain his circumstances.  Solving his first problem leads to a much more perilous second one--the pit he cannot see in his cell.

I think that most readers would probably say that the central pit in the room is the first danger, and the body slicing pendulum is the second danger. That makes a lot of sense as an answer especially when a reader considers that the title of this story is "The Pit and Pendulum." However, I don't think the pit is the first danger. I think the first danger is the complete and total darkness that the narrator opens his eyes to. He even admits that he fears opening his eyes; however, he doesn't fear seeing horrible things. He fears seeing nothing. The narrator then gets up the courage to open his eyes, and his worst fears are confirmed. The darkness is unbelievable.

It was not that I feared to look upon things horrible, but that I grew aghast lest there should be nothing to see. At length, with a wild desperation at heart, I quickly unclosed my eyes. My worst thoughts, then, were confirmed. The blackness of eternal night encompassed me.

The darkness is so oppressive that the narrator struggles for breath, and he finds it difficult to remain calm and use reason. This unbearable darkness is the first danger because of how it could affect him mentally and emotionally. Because he can't see anything, his imagination threatens to take over completely.

I felt nothing; yet dreaded to move a step, lest I should be impeded by the walls of a tomb. Perspiration burst from every pore, and stood in cold big beads upon my forehead.

The darkness could drive him insane. It could drive him to panic. It could drive him to give up. The darkness is a danger because it limits his ability to obtain information and process what is and what is not dangerous. If the room had even a sliver of light, then the pit itself is no longer dangerous. It would be visible and avoidable.