"The Old Dude's Ticker" is a short story written by Stephen King. Although written decades earlier, it was first published in the NECON XX Commemorative Volume in 2000 and later reprinted in The Big Book of Necon in 2009. It is a homage to Edgar Allan Poe's "The Tell-Tale Heart", adapted to take place in the Vietnam War era and incorporating the slang of the time
Plot Summary
Richard Drogan, a veteran of the Vietnam War, lives with an elderly man referred to only as "The Old Dude". The Old Dude has a cataract in one eye that frightens the narrator, so much so that he plans to murder the old man. After several nights of watching the Old Dude sleep by shining a pen-light through his door, he illuminates the old man's diseased eye, which is open. The Old Dude had been awake for some time, and the narrator speculates that he was very afraid and trying to calm himself down. Seeing the eye, however, drives Drogan into a rage.
The narrator claims to have very sensitive hearing from his military service, and smothers the old man for fear of the neighbors hearing the man's heartbeat. He dismembers the body and conceals the parts beneath the floorboards.
The police arrive the following morning; a neighbor summoned them after hearing a yell in the night. Drogan invites them in, but soon hears a rhythmic thudding sound that he believes to be the Old Dude's beating heart. Convinced that the police can hear it as well, he confesses to the crime.
In a paragraph at the end, we are told that the preceding story had been a statement taken from Drogan during the course of the investigation. It is revealed that Richard Drogan is actually an alias for Robert S. Deisenhoff, an escapee from a Veterans Hospital.