We have to make a continuous story, but we can only say one sentence at a time.
i.e.
I say:
"Once upon a time there was a powerful witch"
The next user would say:
"And she lived in a beautiful mansion"
The next user:
"On top of mount everest with no heating"
And we have to make this into a story when you think it's time to end you will put the last sentence and at the end of it say "The End" then the next person will start another with "Once Upon A Time..." And it goes on to make the wackiest of appropriate stories.
I Shall Start!
Once Upon A Time, there were four children; Billy Bob, Bobby Bill, Bill Bob, and Suzie.