Something like Gurren Lagann or Advent Children, then? Yeah, that'd work too. Except that in that case it probably wouldn't be best to end it with Third Impact, but now I'm getting ahead of myself.
I was thinking of crowdsourcing more along these lines: Someone outlines what's going to happen in the next few chapters. Someone else says 'that makes no sense; character A is acting way OOC.' Yet another person says, "Faction X wouldn't make that move, it's suicidal!!!" Another one says "Faction Y wouldn't think of that move based on the information they have available." And yet another says, "Faction Z won't keep quiet about this, they need to move now!" And one more says, "By rule of cool, event Q needs to happen NOW!!" Someone else says, "Also, event P makes no sense given the rules of this universe, it needs to be axed."
And after about a week of such squabbling, we've arrived at a coherent plot in which every character and faction acts in their best interests, based on the knowledge available to them and in accordance with their modus operandi and their competence. So someone writes that up while we move on to arguing about the next chapter.
This seems to me the simplest way of writing a fridge logic-free massively multiplayer crossover in which thirty xanatos pileups are inevitable.
I'll tap out of this discussion for a while now, waiting to see what other people say.
Going through expiring predictions reminded me. Just as we did for 2010 and 2011, it's time for LessWrong to make its beliefs pay rent and give hostages to fortune in making predictions for events in 2012 and beyond.
Suggested topics include: Methods of Rationality updates (eg. "will there be any?"), economic benchmarks (price of gold has been an educational one for me this past year), medical advances (but be careful not to be too optimistic!), personal precommitments (signing up for cryonics?), being curmudgeonly about self-improvement, making daring predictions about the future of AGI, and so on.
As before, please be fairly specific. I intend to put most predictions on PredictionBook.com and it'd be nice if they weren't too hard to judge in the future.
(If you want advice on making good predictions, I've tried to write up a few useful heuristics I've learned. So far in the judging process, I've done pretty well this year, although I'm a little annoyed I got a Yemen prediction right but for the wrong reasons.)