What do you think of the Gravity Falls AU One of Us?
I’ve written some headcanons/almost-ficlets for it. (1 2 3) (I’ve actually got a fourth one pretty much written in my head that I should just type out and post sometime.)
I’ve mentioned that I personally don’t think Bill’s offer was genuine–he was just trying to hurt Ford. He knew him well enough to know that the taunt that would cut Ford the most deeply was one that implied he was like Bill and his friends. A freak, a monster. An evil, corrupt creature that’s brought about the end of the world.
Not that that means anything where an AU is concerned! :D AUs can go anywhere, whether it’s canon-plausible or not.
Still, the only way I can personally see Ford joining Bill while staying in character is if he’s joining him with the intent of stabbing him in the back, so that’s the direction I take my headcanons in.