So here's the idea, I'll start by making up a part of the story. Each subsequent part of the story may be written by someone different and may or may not expand on the previously written part. For example:
Part one: Once upon a time there was a thing that happened.
Part two: The thing that happened was quite unsure why it happened but it made a solemn promise to understand why such a thing could happen.
Part three: Eventually the thing figured it out.
Part four: But then it got hit in the head by a rogue baseball and forgot again....
The goal is to see how far we can get the story to go.
I'll start by writing the first part. The rest is up to you.
Here we go:
Alas, there were too many tomatoes for her to reconcile. She began to ponder the relevance that the plump, red fruit had over the situation.