"The Daemon Lover"
from The Lottery and Other Stories, by Shirley Jackson
Interesting, but so unsatisfying... I don't usually like open-ended tales, and this one was particularly depressing.
...You know, maybe Shirley Jackson wasn't such a great idea, right now, after all. (g) If nothing else, the real world (or at least my corner of it) seems much brighter by comparison, after a trip through her shadows.