This tool is from Pantomimepony, where you can find many other such tools and resources.
random story ideas
This plot generator creates original and random storylines for plays, novels, short stories, soap opera, TV series or a movie script. The plotlines generated are not guaranteed to make sense but they do inspire writers by triggering a creative chain of thought. Most of the results might be off-the-wall but some are pure gold. Keep trying and sooner or later the perfect idea will appear. Some plots sound like a short story; some will fill a novel or could even be the start of a huge franchise.