I think it would be really fun to start a ficlet. I start with a few sentences then someone else reblogs and adds more and then it just keeps getting added to until it’s a whole story. Then a chunk of the fandom has written Castle fanfiction story….
Yeah this sort of thing definitely requires people to check the notes, and see where the last person left off.
About 1 million years ago, when most fandom was conducted by messageboard and email, we used to do this a lot. You’d get a few divergences, but most people would be very careful to try to follow a chain.
But if the worst case is there end up being a couple different fics, that might be a plus…
If we do this, we need all participants to tag their posts so that the posts can be found (tracked?) easily… Something like #castlefandomfic or whatever