Once upon a time there was a bloodsucking vampire whom we shall call Cradula.
The vampire was, of course, very cruel, but apart from that he also lacked all the traces of civilisation that others of his kind possessed. He was not tall, pale, svelte and elegantly dressed, and if anyone gave him a red-lined black cloak he wouldn't know what to do with it. Far from romancing beautiful women, he could hardly put two sentences together without devolving into a string of curses. He was bow-legged, ugly, thuggish, with straggly hair, and such appalling personal hygiene that he had to approach his prey from downwind so they didn't smell him coming.
Cradula lived in an empty old house, a house so long vacant that everyone had long forgotten when it had been built and whether it had had a name. There, in the basement, he had a bed in a grave cunningly disguised as an old chest with a seat on the lid. Every night, once darkness had safely fallen, he would crawl out of his entombment, lifting the top of the chest away, clamber clumsily through a broken skylight, and go hunting. Before dawn, more often than not still hungry, he would drop with all the grace of a sack of potatoes through the skylight and shamble into his grave again.
For as long as Cradula had lived in the old house, it had been empty, but one day there was the noise of doors grating open, furniture being moved, the busy sounds of hammering and sawing, and before Cradula knew it - that is, before the poor vampire woke at the crack of dusk - the house was no longer empty. A family of four had moved in, father, mother, son, and daughter. The first thing Cradula knew of them was the sound of the daughter singing and playing the guitar in her new room upstairs. She sang and played atrociously.
Of course, Cradula didn't know that she sang and played so badly. He was far too uncultured to care about that at all. All he wanted to do was to go out and drink his nightly portion of blood, and the confounded caterwauling was giving him a headache, so he went straight to his skylight.
Whereupon he had a shock. The skylight had been removed and the space bricked in! And the basement, where he had spent so many uneventful decades, was no longer empty, it was almost full of heaps of coal for the furnace that hadn't been used in so long that Cradula hadn't even known it was there.
The poor vampire was in a state. He couldn't get out of the basement, because of the skylight. He couldn't get out through the door up into the house, because it was locked. And he hadn't had any luck hunting in days, so he was starving. And, on top of everything, he was so illiterate and uneducated in the ways of humans that he was frightened out of his wits, not that he had many.
It was just as he was gibbering to himself in the corner that the light in the ceiling went on and someone turned the key in the door leading upstairs...
The night was cold, and the mother, deciding the house needed heat, had ordered her husband to start up the furnace. "And don't come back till it's burning nice and hot," she commanded. "Do you hear?"
Cradula, thrilling with terror, shot back into his grave so fast that the coal dust of his passage still hung in the air like behind a cartoon character who'd taken off running. The father came grumbling down, muttering about the television he should've been watching, and shovelled the furnace full of coal. Then, setting the load alight, he looked around for a place on which to sit while waiting for the fire to take hold.
The only place to sit was the nice old chest with the convenient seat on the lid...
Cradula may have been terrified, but he could now smell the proximity of the human blood coursing through human veins. His fangs grew wet with saliva, he reached up, flipped open the lid of the chest, dragged the father inside, and drank him to a shrivelled husk in less time than it takes to write of it. Then he slammed shut the lid, belched loudly, and went contentedly to sleep.
What about the corpse? He kept it right there with him in the grave. I told you he was a slob.
After an hour, the mother - by now warm - began to wonder why her husband hadn't come back up. Was he drinking down there? She decided to come down for a look.
"Are you hiding behind that coal?" she roared, not seeing her lesser half anywhere. She stamped around the basement, poking here and there, and then, baffled, plonked her ample bottom down on the lid of the chest, so hard that it woke Cradula.
And, because he smelt her blood and was an uncouth glutton, he pulled her down and drank her dry as well, then closed the lid and went back to sleep.
Some time after that, the fire in the furnace began to die down. The daughter began to shiver a little. "Hey, twerp," she ordered her brother, between songs, "go down and put more coal in the damned furnace."
"Go yourself, " said the brother, who was busy with a video game.
The daughter stuck it as long as she could then wandered down to the basement to stock up the furnace. Afterwards she looked around. "I wonder what it would sound like if I sang in here, " she said, and, sitting down on the chest, resumed her guitar playing and singing.
Cradula, of course, had been awakened by the terrible noise, and, being without any refinement, didn't recognise music when he heard it. He knew only that there was a fresh supply of blood sitting over him. So he opened the lid, yanked in the girl, and drank her dry as well before pushing the lid shut, and, putting her corpse with those of her parents, went back to sleep.
By and by the son finished his game and wondered where everyone was. He looked up and down in all the rooms of the house, but they were all empty. Then he came down to the basement, searched around, and went away upstairs again. Later that night he came down to stock up the furnace, searched for any trace of his parents or sister, found nothing, and stood scratching his head. But Cradula didn't grab him and drink him dry, not then, and not in the many, many days that have passed since. The son still goes down to the basement every day and Cradula can't lay a finger on him.
Why not?
Simple!
The son never sits on the brutish vampire.