A newcomer moves into a quiet suburb. He goes to the eight nearest houses and greets the families. There are around twenty characters all told, but they’re quickly sketched with their hobbies and their characteristics. All of them are happy and get on well with each other.
And the newcomer, in small, untraceable actions, destroys every single one of them.
This isn’t one of those stories where someone realizes what’s going on and it’s a battle of wits between the detective and the newcomer. There is nobody to stand against the newcomer. The story is an exercise in cruelty, in seeing how such contented and peaceful families can collapse into loathing and fury with a few well-placed actions. It plays nicely with the paranoia that anyone could, if they had the motive, methodically ruin every aspect of your life.
I found this an uncomfortable story to read even as I was mesmerized, like watching a long chain of dominoes topple, one after another.
(Incidentally, in researching this I found F. Paul Wilson wrote a sequel entitled ‘Recalled,’ published in the Richard Matheson tribute anthology ‘He Is Legend.’ I’ll have to keep an eye out for it.)
The Distributor by Richard Matheson
Availability: Print only
Word count: 4,900
First published: Playboy, 1958
Where to find it: The Incredible Shrinking Man, collection, 2001, Tor
Nightmare at 20,000 Feet, collection, 2002, Tor
My Favorite Horror Story, edited by Martin H. Greenberg & Mike Baker, 2007, ibooks
Richard Matheson: Collected Stories Vol 2, 2005, Gauntlet Press
Ten to Infinity 
Matheson also adapted the story into an unfilmed speculative screenplay, published in the collection DUEL & THE DISTRIBUTOR (which I edited), along with his PLAYBOY story “Duel” and the teleplay he wrote for Steven Spielberg’s 1971 film version. For more on his screenwriting work–both filmed and unfilmed–see my book RICHARD MATHESON ON SCREEN (http://www.mcfarlandpub.com/book-2.php?id=978-0-7864-4216-4).