Our anonymous protagonist is the caretaker of an old man with, as the protagonist states, "evil eye similar to a vulture's" The protagonist loves the old man but cannot stand his eye, so he decides to kill him.
Our soon-to-be killer has snuck into the old man's room every night at midnight for several nights in a row, but one night as the protagonist enters the old man shoots up and exclaims "WHO"S THERE?" The protagonist stays still and doesn't move a muscle hoping to not be seen by the old man. Suddenly, a low moaning noise of mortal terror comes from the old man. The old man is dead. The murder chops him up and hides him under the floorboards
Later that evening the murderer is asked by two detectives investigating a scream that was heard if he knows anything about it. The murderer lies and claims it was just him screaming from a nightmare. he invites the detectives in for a talk when suddenly he hears it, a low pounding noise that progressively gets louder. The noise began to drive him insane and at last the murder screams. "DISSEMBLE NO MORE! I ADMIT THE DEED TEAR UP THE PLANKS! HERE, HERE! IT IS THE BEATING OF HIS HIDEOUS HEART