Knock

There is a sweet little horror story that is only two sentences long:
“The last man on Earth sat alone in a room. There was a knock on the door…”
Two sentences and an ellipsis of three dots. The horror, of course, isn’t in the two sentences at all; it’s in the ellipsis, the implication: what knocked at the door? Faced with the unknown, the human mind supplies something vaguely horrible.
But it wasn’t horrible, really.
The last man on Earth—or in the universe, for that matter—sat alone in a room. It was a rather peculiar room. He’d just noticed how peculiar it was and he’d been studying out the reason for its peculiarity. His conclusions didn’t horrify him, but it annoyed him.
Walter Phelan, who had been associate professor of anthropology at Nathan University up until the time two days ago when Nathan University had ceased to exist, was not a man who horrified easily. Not that Walter Phelan was a heroic figure, by any wild stretch of the imagination. He was slight of stature and mild of disposition. He wasn’t much to look at, and he knew it.
Not that his appearance worried him now. Right now, in fact, there wasn’t much feeling in him. Abstractedly, he knew that two days ago, within the space of an hour, the human race had been destroyed, except for him and, somewhere, a woman—one woman. And that was a fact which didn’t concern Walter Phelan in the slightest degree. He’d probably never see her and didn’t care too much if he didn’t.
Women just hadn’t been a factor in Walter’s life since Martha had died a year and a half ago. Not that Martha hadn’t been a good wife—albeit a bit on the bossy side. Yes, he’d loved Martha, in a deep, quiet way. He was only forty now, and he’d been only thirty-eight when Martha had died, but—well—he just hadn’t thought about women since then. His life had been his books, the ones he read and the ones he wrote. Now there wasn’t any point in writing books, but he had the rest of his life to spend in reading them.