The narrator of this story tells you his "perfect" plan to kill an old man, then
takes you through the process of doing it. He might get away with it too except
he starts hearing things...
"I kept quite still and said nothing. For
a whole hour I did not move a muscle, and in the meantime I did not hear him lie
down. He was still sitting up in the bed listening; Ч just as I have done, night
after night, hearkening to the death watches in the wall."