I keep casting about for themes for story ideas. Just looking for something that crackles and energizes a plot. Last night, looking at myself in the mirror, I gave consideration to the old concept of the doppleganger. Good enough for Poe. Good enough for me.
A doppleganger is defined as
Etymology: German Doppelgänger, from doppel- double + -gänger goer
1: a ghostly counterpart of a living person
2 a: double 2a b: alter ego b c: a person who has the same name as another
This concept of duality deserves a greater examination than is about to be offered on a blog, but it's intriguing to think of how fascinated we have been with this concept through history. Good and Evil. Christ and Anti-Christ. What would happen if when looking in the mirror we thought that there was something different about the image staring back at us, something unaccountable?
Is there horror to be found in this concept? Not overtly. But I think the idea mines discomfort from the need for individuality. If there is a doppleganger out there, then perhaps we aren't so unique. And perhaps everything we thought we knew about the nature of existence, or at least or place in existence, can be called into question.
Some folk truly believe in the idea of their double being out there somewhere. Some have explained it as a manifestation of out of body travel.
Consider if you will the case of Emilie Sagee. With thirteen students looking on, this 32 year old French woman was writing lessons on a classboard when her exact double appeared next to her, writing as she wrote. I think the documentation on this is questionable, probably an 1800's version of tabloid journalism, but it still captures the imagination.
And although we don't know of Sagee, we do know the names Guy De Maupassant, Percy Byron Shelley, and Queen Elizabeth---all three claimed to have seen their double at one time or another.