"August Heat" (1910)

Because it's convenient for things to have a starting point, and because it makes a good story that way, I'm assigning the beginning of modern horror fiction as we understand it to 1816, when E.T.A. Hoffmann published "The Sand-Man" and when the Shelleys, Mary and Percy Bysshe, gathered in Geneva with Lord Byron and his doctor, John William Polidori, and had a friendly competition to write ghost stories. The result was Frankenstein and "The Vampyre." Nearly a hundred years later, W.F. Harvey's very short story about the dog days of summer depends to a certain degree on familiarity with horror fiction conventions as they had developed. It's more along the lines of a knowing joke, and the punchline is "uncanny." It's not as witty as Saki but has an undertone that dares you to laugh, and then dares you not to laugh. It tells us things that don't make sense as if they do. It captures a little of the insanity that happens when it's still sweltering hot even at night in August. It's not the heat, it's the humidity.

On one of those very hot days an illustrator (who is also the first-person narrator) is seized in the morning with an impulse to sketch a man at trial just as he is sentenced. He thinks the picture is pretty good, if he says so himself. "The feeling that his expression conveyed was not so much one of horror as of utter, absolute collapse." Then the illustrator walks aimlessly for several hours. He finds himself at the shop of a stonemason. On an impulse he enters it. It's the man in his sketch! And he's working on a gravestone. And on that gravestone is the name of the narrator, with his birthdate and today's date (August 20th, 190–),already chiseled in. This work is the result of an impulse on the mason's part. The two don't know one another, have never met, and soon agree it's a strange and dangerous situation. They decide to stay together the rest of that day for mutual safety. Of course this story is short and moves quickly because it's so ridiculously impossible. At the end of the day, between 11 p.m. and midnight, the narrator is recording his account in the mason's workshop while the mason tidies up. The story ends:

The air seems charged with thunder. I am writing this at a shaky table before the open window.
The leg is cracked, and [the mason], who seems a handy man with his tools, is going to mend it as soon as he has finished putting an edge on his chisel.
It is after 11 now. I shall be gone in less than an hour.
But the heat is stifling.
It is enough to send a man mad.

Harvey couldn't resist the broad wink of "I shall be gone in less than an hour," but it is actually hard for me to imagine this complacent scene turning into frenzy and murder within the hour. And maybe it doesn't! We're never told. But that's the idea. The improbability, and the uncertainty, thus keep it more in the realm of merely cerebral, a macabre joke predicated on reader expectations. But it's sparkly and swift and maybe even uncanny if you turn it around in your head enough. It's been done on radio plus in the early '70s DC Comics adapted it for one of their horror titles. Night Gallery should have done it too. That show always did like to make people sweat.

The Big Book of the Masters of Horror, Weird and Supernatural Short Stories, pub. Dark Chaos
Read story online.