This is a game I first played in the old days when I still played Tribal Wars. The rules are as follows (some I have thought up for clarity):
1) Post only three words in your part of the story. You can post more words, but just not as part of the story.
2) Your words must make a logical continuation of the previous words. However, the story can go in any way you please.
3) Do not post until either someone else has posted or a week has passed. This only includes posts adding to the story.
I shall start.
"Once upon a..."
I look forward to seeing how this goes.