"The old man sprang up in the bed, crying out, ‘Who’s there?’
I kept quite still and said nothing. Presently, I heard a slight groan, and I knew it was the groan of mortal terror. It was the low stifled sound that arises from the bottom of the soul when overcharged with awe. I knew the sound well. I knew what the old man felt, and pitied him although I chuckled at heart. I knew that he had been lying awake ever since the first slight noise when he had turned in the bed. His fears had been ever since growing upon him. He had been trying to fancy them causeless, but could not. He had been saying to himself, ‘It is nothing but the wind in the chimney, it is only a mouse crossing the floor’. Yes he has been trying to comfort himself with these suppositions; but he had found all in vain.
Now, I say, there came to my ears a low, dull, quick sound, such as a watch makes when enveloped in cotton. I knew that sound well too. It was the beating of the old man’s heart. It increased my fury as the beating of a drum stimulates the soldier into courage.
But even yet I refrained and kept still. I scarcely breathed. Meantime the hellish tattoo of the heart increased. It grew quicker and quicker, and louder and louder, every instant. The old man’s terror must have been extreme! It grew louder, I say, louder every moment! And now at the dead hour of the night, amid the dreadful silence of that old house, so strange a noise as this excited me to uncontrollable terror. Yet, for some minutes longer I refrained and stood still. But the beating grew louder, louder! I thought the heart must burst. And now a new anxiety seized me — the sound would be heard by a neighbour! The old man’s hour had come! With a loud yell, I threw open the lantern and leaped into the room. He shrieked once - once only. In an instant I dragged him to the floor, and pulled the heavy bed over him. I then smiled gaily, to find the deed so far done.
But for many minutes the heart beat on with a muffled sound. This, however, did not vex me; it would not be heard through the wall. At length it ceased. I removed the bed and examined the corpse. I placed my hand upon the heart and held it there many minutes. There was no pulsation. He was stone dead. His eye would trouble me no more.”
-Edgar Allan Poe, The Tell-Tale Heart