This Story has scary parts.

When I was a young boy, there was a strange old man in our neighborhood named Frank Samuels. We all called him Frownin' Frank because he was awful ornery and none of us every saw him smile. He had a mangy old dog he called King that always used other people's yards for a bathroom.
Every morning and every evening, Frownin' Frank would take King for a walk and let him do his business in someone's yeard. I figure King was Frank's only friend.

One evening, while we were playing in the street, Frank came walking down the road, hollering, 'King! King! here boy!'
He hollered at us, 'You boys seen my dog?'
We hadn't and we told him so.
Frank just kept on frownin' and yelling for his dog. About an hour later, he came back looking pretty depressed and headed for his home. He hadn't found King.

Frank looked all around his yard, in the shed out back, under the house and in the bushes in the back yard - no sign of King anywhere.

Finally, he went inside, took off his coat and shoes, and sat down in his chair. He knew he had to call the dog pound. Just as he picked up the phone, he heard a noise like scratching and whining upstairs. He put down the phone and quietly walked up the stairs in his socks so he could still hear the noise.
When he got to the top, the sound came from still higher up - in the attic! He climbed the stairs up to the attic door, making no sound in just his socks.

He stood outside listening, but he didn't hear a thing. Then he opened the door, stepped in, and -

(Now SCREAM LOUDLY!)

At this point, don't say anything more. Just sit there as if you have finished the story. Somebody will ask, 'Why did he scream?'
You reply, 'You'd scream too if you stepped on a nail in your bare feet!'