Okay so I came up with an au idea, and recently I realized I came up with it over two years ago, but never shared it. Since this is the anniversary of Not What He Seems, I figured it was time to share it.
So here it is, (heavily inspired by The Parent Trap)
Rival Halves AU
First major difference in this AU, Gravity Falls doesn’t exist (at first…I’ll come back to that) instead the town is two separate towns that hate each other, to a point that they have a wire fence separating the towns. For now, since I can’t think of better names, the towns are Falls Ville and Gravity Ville. When Ford comes to the area to study the paranormal activity, he has his house built outside the borders of both towns so he can go to either town whenever he wants without causing a ruckus.
Second major difference is that after Ford gets lost in the portal, instead of Stan needing 30 years to get Ford back, he was able to open the portal and save Ford around the time Mabel and Dipper were born. When Ford gets back to his dimension, the brothers fight for hours over whether or not Stan should have reactivated the portal. After a few hours, the brothers start to calm down and they decide they are being immature and that they should simply forget the whole thing and get along like adults (but they don’t talk it out and resolve any issues, they simply decide to stop fighting and try to be best friends again). A few weeks later, Dipper and Mabel are orphaned by a fire and Stan and Ford get custody of them. Everything is fine at first but slowly the grunkles start fighting again, as they have built up tension from not working out their issues, and they have different parenting styles that are setting them off on each other. After a few weeks of brutal arguments, the brothers come to the realization that they are not creating a happy and healthy environment for their niece and nephew to grow up in. They decide the best thing to do is each take a kid, raise them on their own, and go their separate ways to stop the fighting. Ford leaves for Falls Ville to raise Mabel, and Stan goes to Gravity Ville to raise Dipper. Neither grunkle is aware the other is simply in the neighboring town, and Dipper and Mabel grow up unaware of the other’s existence.
Since Dipper and Mabel grew up with their respective uncles, their personalities are a little different. Dipper is still very nerdy, but after being raised by his con artist uncle, he’s also tougher, more rebellious and has gotten into more than his fair share of trouble. He and Stan have even committed a few felonies as a team, usually with Dipper being the brains behind the operation. Meanwhile, Mabel is still eccentric and glitter loving, but after being raised by her scientist uncle, she grew to have a love for science. Similarly to how Dipper uses his smarts to commit crimes or con people, Mabel uses her smarts to beautify the world. One of her creations is mood nail polish, nail polish that changes color depending on your mood. Ford loves to brag about Mabel’s accomplishments.
In the spring of 2012, a fire catches around the fence that separates the rival towns. The fire spreads quickly, but luckily no one is hurt, and few people are minorly injured. Unfortunately, the fire took out a lot of each town. The mayors of both towns get together and agree that the only way their towns are going to survive the aftermath of the fire is if they come together as one town and help each other out. And thus Gravity Falls is created—much to the dismay of many townsfolks. Dipper’s school was destroyed in the fire, so he and Mabel meet for the first time in years when they have a class together at Mabel’s school. Due to their very different personalities, they don’t like each other when they first meet. In fact, they even get into a fight at school. They go home and tell their uncles about the fight they got into with “this dumb girl” and “this jerk in class.” Over the years, Ford has gotten into the habit of taking Mabel to the park when she’s upset, so he takes her to the park after hearing about her bad day. After hearing about Dipper’s day, Stan decides the kid needs a distraction, and since they’d been wanting to check out the new half of town to see who good targets would be to scam, they also decide to go to the park. This is where the entire family meets again and the truth comes out to Dipper and Mabel.
After shooing the kids off to deal with their feelings of betrayal, the grunkles decide to talk. They agree that while they still don’t want to see or talk to each other (they didn’t exactly get along last time after all) they also don’t want the same thing that happened to them to happen to their niblings. So they devise a plan. That night they inform both kids that one day, they will be living together and switching between their unlces’ houses, but only when they are ready to put up with each other. Until then, they are going to switch houses back and forth so they can get some quality time with the uncle they haven’t seen in years (so basically one week they would switch houses and Dip would stay with Ford while Mabel would stay with Stan and then the next week they’d switch back and reunite with the uncle that raised them and just go back and forth), and it’s their job to set it up (that way they are forced to talk to each other). Dipper and Mabel switch houses individually until summer vacation when they agree they could stand to live together. The au’s versions of episodes revolve around the kids switching between their uncle’s houses and the townsfolk learning to put aside their differences and accept that they are not rivals anymore, all while Dipper and Mabel are learning to get along, and eventually trying to get their uncles to get along. The au equivalent to the finale will end with the entire Pines family getting along and living together in one household.
Gravity Falls and Other Related Stuff 