The narrator is intensely nervous, but claims that he isn't insane.
The narrator explains to us that he has a "disease" that makes his "senses" super powerful. According to him, this is different than an insane person, whose senses are completely gone, or at least very weak.
"Hearing" is the narrator's most intensified sense, and claims to be able to hear everything going on in "heaven," "earth," and most of what's going on in "hell."
Now, the narrator will further prove his sanity by telling the following story.
(Note: When the narrator says "Hearken!" he means listen up.)
The narrator's story begins with an "idea," an idea that turns into an obsession. (He doesn't yet reveal to us what this idea is.)
There's no reason for it. In fact, the narrator "loved the old man," who has always been really cool. It isn't about the old man's money either.
See, the narrator thinks it might have been the old man's freaky eye that started the idea: "He had the eye of a vulture – a pale blue eye, with a film over it" (2).
Whenever the old man's eye looks at the narrator, the narrator's blood freezes.
This has gotten to be too much for the narrator to handle. He decides that the old man had to die, so the narrator won't have to ever see the eye again.
Now the narrator begins defending his sanity again.
This time the argument is that insane people don't have any knowledge or skill, whereas the narrator plans everything well and is extremely careful.
(In the text, "foresight" means you can predict things, or see them before they happen. "Dissimilation" means acting a certain way to hide the true feelings.)
The narrator is super-sweet to the old man all week before the killing goes down.
Each night of the week, at almost 12am, the narrator goes to the old man's room and cracks the door enough to put in a "a dark lantern" (3).
The narrator's lantern is lit, but it has plates around it that can be opened and closed to control the amount of light coming out. The narrator has it closed so no light shines out.
After the lantern, the narrator pokes in his head through the door.
He's afraid of waking the old man, so it takes an hour for him to stick his head in the room.
The narrator argues that this is proof that he's not insane. How could the he be insane, he asks, and be so careful at the same time?
Next, the narrator opens the lantern, just enough to let a tiny bit of light shine on the old man's eye.
But the narrator can't kill the old man, because he won't open up his eye. See, it's the man's "Evil Eye" the narrator has a problem with, not the man himself.
Every morning, the narrator comes into the old man's room, and asks him how he slept.
The old man would have had to be pretty "profound" (deep) to guess that the narrator had been spying on him while he sleeps.
On the eighth night, the narrator repeats the process, opening the door more carefully than usual.
He feels at the height of his "power" and can't even believe his own "sagacity."
("Sagacity" means quick and clever thinking. It also means an excellent sense of smell. These days, the word is only rarely used in that second way, but considering what the narrator said about his heightened senses, both meanings might apply.)
Anyhow, the narrator feels intensely that he's going to win this game, and is really enjoying the fact that the old man is asleep and had no idea what the narrator is doing.
The old man moves in his bed.
The narrator doesn't draw back. The old man is afraid of "robbers" and keeps his "shutters" closed. The room is so dark that there is no way the old man can see the door opening.
Just as the narrator gets his head through the door and is about to shine the light, he makes a little noise, and the old man jumps up and says, "Who's there?"
So the narrator doesn't move for an hour. The man must still be sitting up, listening ("hearkening") to "the death watches in the wall" (4).
("Death watches" are beetles that often live in tunnels they make inside of walls. They hit their heads on the tunnel walls to attract mates. For more info, click here.)
Then the narrator hears a "groan of mortal terror" (5). He knows it's a groan of terror because the narrator groans like that, too.
He feels sorry for the man, but is laughing inside, knowing the old man is scared out of his mind and had been trying to convince himself there is nothing to fear.
But, according to the narrator, the man knows there really is something to fear, and knows he's about to die.
The narrator waits and waits, and then decides to open his lantern just a little bit. He opens it "stealthily" (that is, "sneakily") and then trains the beam on the man's "vulture eye" (6).
It's open. The eye is open. The narrator gets mad when he sees it. Then he can hear, due to his heightened senses, the old man's heart beating dully.
So the narrator doesn't move. He just keeps the light shining on the old man's scary eye.
The heartbeat gets louder and faster as the old man gets more and more scared.
The narrator reminds us to "mark" (or notice) that he was and still is a nervous person.
Finally, the noise gets so loud the narrator is afraid the neighbors are going to hear it.
So the narrator screams, opens the lantern all the way, then jumps into the old man's room.
The old man only screams one time, and the narrator drags him off the bed and then yanks "the heavy bed over him" (7).
The narrator smiles. The heartbeat continues, but soon stops. The old man is dead.
The narrator moves the bed and checks out the body, just to be sure.
He's definitely dead.
The narrator says that if you still think he's insane, you won't after hearing what he does with the body.
First the narrator cuts the arms, legs, and head off the body, then hide the body parts under some loose boards in the floor. ("The scantlings" means the limited space under the floorboards.)
There isn't even any blood on the floor, because the narrator is too smart for that and cuts up the body in a bathtub.
By then it's 4am and still dark.
There's a knock on the door.
Not worried, the narrator answers the door.
Three policemen come in. The neighbor heard a scream and thought something bad was going on and called them.
The narrator tells them he screamed during his sleep. He claims the old man is out of town and invites the officers to search the place, which they do.
Finally, the narrator takes them to "the old man's chamber" (or bedroom) and even brings in some chairs for them all to sit down.
The narrator puts his chair on top of the place where the body is hidden.
The cops aren't suspicious anymore, and the narrator chats with them happily, but soon gets tired and wants them to go away.
His head is really hurting, and there is "a ringing in [his] ears" (9).
It gets louder and louder and the narrator talks to try to get rid of the sound. The police officers drone on.
Uh-oh. The noise isn't coming from the narrator's ears at all.
As the noise gets louder, the narrator talks more and more wildly. It sounds like the ticking of a watch wrapped up in cloth.
The policemen don't seem to notice the noise.
The sound torments the narrator, who starts getting out of control, arguing with the police officers, making wild "gesticulations" (or gestures), pacing, etc.
But the noise just keeps getting louder.
The narrator can't take it. He is convinced the police officers know everything and are just toying with him.
The noise gets so bad the narrator will to do anything to make it stop, and to stop the lying police officers from smiling at him, pretending not to know what's going on.
So the narrator knocks the policemen to the ground and blurts out, "Villains! [D]issemble no more! I admit the deed! – tear up the planks! here, here! – It is the beating of his hideous heart!'"
(To "dissemble" is to pretend not to see or notice something.)
And that's the end of the narrator's story – his proof that he's not insane.