In honor of Back to the Future day, I was going to post my Wikipedia summary of Back to the Future IV (which I started from scratch this morning and which escalated quickly). The movie would star Christopher Lloyd (with Michael J. Fox in two cameos) and would explain the difference between the 2015 of BTTF II and the real 2015 (hint: this is the bad 2015). It's a plot line I've had in my head for years.
But of course, it became a full treatment thing and I've found and addressed a million holes (which in turn created a million more holes), and rewatching all three films today makes it seem rudderless by comparison, so I guess my treatment will need more ... dare I say it ... time. Huh-huh.
In lieu of that, have fun with this.