What if Bud Gleeful had exposed his son to the benefits of the Society of the Blind Eye? All characters belong to Alex Hirsch and Disney, not me.
Gideon Erased
After Bud told Gideon he had some guests (those awful Pine Twins who had conspired to break Gideon's heart) he went back inside the Mystery Shack to look for anything worth taking home, before the Shack was torn down to make room for Gideonland.
Not long afterward, he heard a shrill whistle from outside. He looked out the diamond-shaped window in the porch door and saw Gideon surrounded by gnomes. The gnomes had fallen to their knees, apparently subdued by his whistle. A moment later, it looked like they were going to carry off only the Pines.
"My poor li'l son," thought Bud. "This will traumatize him for life, unless I get the Society to help."
He phoned Blind Ivan, who said he would assemble the others.
Gideon came into the house, giggling, with a book under his arm.
"I've got it! I finally got it!" said Gideon. He shouted at his parents, "Get out!"
Mrs. Gleeful left off her vacuuming and exited quickly. Bud also left, to don his Blind Eye robes and join the others who had arrived outside.
When they entered, Gideon had two books on the living-room table and he was shouting something about them. They grabbed him and put a bag over his head, which was standard policy for Blind Eye interventions.
When they got Gideon down into the interrogation room and fastened to the chair, they removed the bag from his head.
"Who are you? What are you doin'?" Gideon demanded.
Blind Ivan spoke for the group, "We are helping you to deal with unpleasant memories. You were attacked by a large group of little men with beards today, were you not?"
"That's nothin'," said Gideon. "I've had a lot of experiences with the supernatural. I even raised a demon, so you'd better not mess with me."
"A more serious case than we thought," said Ivan.
He adjusted the mind-wiper to "Experiences of the supernatural," and used a higher power setting than he had originally planned.
Stan Pines sneaked into the Mystery Shack. There didn't seem to be anyone around, and he might be able to get into his stashes of cash. (He hid money in the Shack rather than use banks, to avoid taxes, but it left him strapped when he was suddenly thrown out).
The main stash of money was in a secret panel under the floor of the living room. He pried it open and got out several bundles of cash, which he stuffed in his pockets.
He looked over the room to see what damage Gideon had caused. To his amazement, he saw two Journals on the table, books 2 and 3. He picked them up.
"After all these years, I finally have them all," Stan said to himself.
He tucked the Journals inside his coat and prepared to leave. Now all he had to do was get the Mystery Shack back, somehow.
As he was heading out the porch door, he ran into Gideon, coming in.
"Stanford Pines, just the man I was looking for," said Gideon.
Stan said, "Gideon, before you have me arrested, listen. I want this place back, and I'll do anything to get it."
"Of course you do," said Gideon. "I've decided this isn't the best location for Gideonland, anyway. Tourists flock to Gravity Falls because of curiosity about the Mystery Shack, miserable as it is. If I remove it, that makes Gideonland the only tourist draw here, and I won't make as much money. I'll put Gideonland near the Tent of Telepathy instead."
"So, we can do a business deal?" asked Stan.
"Yes. I'll give you back the deed, and you lend your support and advertising to the Tent of Telepathy and Gideonland," said Gideon. "Like that deal you almost made with my father."
"It's a deal," said Stan."Except Mabel isn't included."
"Dear Mabel," said Gideon. "I wish I knew why she dislikes me so much."
"I think it has something to do with you hurting Dipper when she broke up with you," said Stan. "He came back one night all banged up, and they said you did it."
"Not that I recall," said Gideon.
"Good answer when you're accused of anything criminal, kid," said Stan.
"I wish I could win back her affection," said Gideon.
"Saving her summer is a start," said Stan. "I put them on a bus home, but they change buses a couple of times on the way. There's still time for me to catch up with them and get them back for the rest of the summer."
"I'm happy to hear that," said Gideon. "I'll have my father bring over official deal papers and I'll give you back the deed tonight. Meantime, you're welcome to take up residence again."
"Thanks, kid," said Stan. "I still don't like you, but I'm glad we can do business together."
"Likewise," said Gideon.
After Gideon left, Stan called the bus company and made arrangements to collect the kids at their next bus station.
He needed to leave soon. But first, he would take the Journals down to the secret level and fire up the Portal. He couldn't wait.