Thanks, Alice. ;-D

Here's another that would go well as a television vignette, I think.

The people here mostly came from Scotland, and mostly from places like Barra and Skye and Benbecula. The old folks believed very much in forerunners, which most often foretold a death. There were many different kinds. Some were knocking sounds, thought to represent the hammering of nails in a coffin. Some were ordinary signs, like a bird flying into the house, or a diamond-shaped crease in a tablecloth, or a dream of a red-headed man. Then there were the ones like this:

A young fellow who lived near Washabuckt in Cape Breton in the 1800s was walking home from a friend's late in the evening. It was very dark on the road, no lights, of course, and no moon. After a while the fellow thought he heard footsteps ahead of him, and he hurried to catch up, as someone to walk with would make the trip go faster. But hurry as he might, he couldn't quite catch up, and though he called out, no one answered.

He became a little angry, because it was very rude of the man not to wait up, and he could now just see that there was a figure of a person ahead of him. At last, as he neared home, the figure stopped, and when it did, the young man quickly caught up and saying angrily, "Why would you not speak to me?", he placed a hand on the figure's shoulder. At that, the figure turned around, and to the young man's horror, he saw in the dim light his own face as if in a mirror, but thin and white and hollow-eyed.

The terrified young man ran as fast as he could to his own house, and told his family what he saw. Soon after, he became ill with consumption (TB) and soon, thin and hollow-eyed from that wasting disease, he died.

And that was the kind of forerunner called a doppelganger.