On the car ride back, they discussed how they might get Dipper's memory back. Mabel suggested her scrapbook; being a glittery account of almost every day of summer they'd had, it was the perfect substitute for that memory cylinder Ivan had smashed.
Dipper was still sleeping soundly when they pulled up to the Mystery Shack, so Soos, Wendy and Mabel carried him up to the attic. They passed Stan on the way, who looked them once over and declared he didn't even want to know what they'd been up to.
If the scrapbook worked as planned – and Mabel knew it would - he wouldn't have to.
Once he was on the bed, everyone was at a loss of what to do.
"Should we wake him up?" Wendy shook Dipper's shoulder, but it accomplished nothing. "Wow, that memory wipe really did a number on him. What should we do, pour some water on him?"
Mabel tapped her chin. "With water balloons?"
"That's a great idea, hambone!"
"Yeah, this totally won't backfire!"
Ten minutes later, and everyone had come back upstairs loaded with water balloons. Mabel threw one at Dipper, but to her surprise it still didn't wake him up. He was now just sleeping in very wet clothes, on a very wet bed.
"Hmm." Soos started to squeez the water balloon. "This isn't working – ah, I'm all wet! Dudes, I should have expected that."
"Maybe we should just leave him alone?" Wendy suggested. "And move him to your bed, he looks kind of..."
"Wet?"
"Yeah, pretty much."
Soos and Wendy waited around for a little, but as the sun set it became apparent they'd have to go home before he woke up. They left promising Mabel to come back the very first thing in the morning and see how it went.
So Mabel was left alone with her sleeping brother. She entertained herself with looking through her scrapbook, at all the wonderful summer memories she'd had with her brother. She couldn't imagine him not remembering any of it; he probably still did, somewhere, right?
She was suddenly jolted from her thoughts when Waddles bumped up against her legs. "Oh, hello Waddles!"She lifted him up onto the bed and turned him to face her brother. "Look! Dipper's sleeping."
Waddles oinked, then jumped onto Dipper's stomach. Dipper yelped and jerked up as soon as the pig's hooves poked him, and he frowned when Waddles started licking him.
"Waddles!" Mabel quickly picked him up. "Are you okay, bro bro?"
Dipper groaned and began to rub his eyes. "Mabel? I just had the weirdest dream..."
"You did?" She picked up a glass of Mabel Juice. "It wasn't about, like, the entire summer we just had at Gravity Falls so I can tell you it was all real and everything goes back to normal, right?"
"No, actually I was in this stone building- wait, this isn't the bus!" Dipper looked around, frowning. "We're in some sort of bedroom, and there's a pig. Where are we, Mabel?"
"Where are we? Haha, well, I'll tell ya! Have a glass of Mabel Juice!"
"What is this, pink lemonade with toy dinosaurs? Pass." He placed it on the floor, and Waddles immediately knocked it over. "I'd really like to know why there's a pig in here. Or where 'here' is."
He didn't remember Waddles at all? This might take a little more work than she expected, but everything was still okay! "You're at the Mystery Shack! And that's Waddles, my pet pig. Don't you remember?"
Dipper's face was enough of an answer. Mabel sighed.
"Look, would you call me crazy if I told you we've already spent more than half of our summer here, and you got your mind wiped by some weird machine?"
"Yes," He said without hesitation.
"Haha, then you're going to think I'm crazy, but-"
Dipper rolled his eyes. "Come on, Mabel. I'm not going to fall for that. You just didn't wake me up on the bus, you carried me into the Misty Hut-"
"Mystery Shack."
"Yeah, that. And then you decided to pull one of those tricks you always pull on me back at home. But this time, I'm not falling for it!" He looked over at Waddles. "Hmm, though that still doesn't explain the pig."
"It's true!" Mabel brought up her scrapbook. "Look, I can even show you how we got Waddles: there was this time traveller-"
"Really, Mabel. A time traveller."
"Yep! His name was Blendin Blandin and he threatened to go back in time to stop our parents from ever meeting." She tapped her chin. "He never really followed up on that, but I can't help but feel he's going to show up in the next twenty minutes."
"Mabel, this is ridiculous." Dipper stood up and made for the door. "I'm going to go introduce myself to Great Uncle Stan; you know, the guy who's we're living with for the summer."
At that moment there was a shout from downstairs. "Kids, I accidentally shoplifted this green paint from the store along with my usual stolen items, so how do you feel about forging some more money tonight?"
"Or, maybe not." Dipper scratched his head. "That's weird, he says that like he knows us."
"That's because he does." Mabel opened up the scrapbook. "Look at all these pages of summer memories! Look at my calendar! You've gotta remember something!"
"Are those... actual photos?"
"Yes!" Mabel then reached under Dipper's bed. "And here's this weird journal you've been obsessed with all summer. You've looked through this thing so much you've gotta at least have some memory of it!"
Dipper flipped through the journal, frowning. "I don't remember anything. You said my mind was wiped by something?"
"Yeah, this memory gun thing."
"This is so... unbelievable. I don't want to believe you, but there's so much not adding up, it almost makes sense." He then frowned. "I still don't know what's going on with this supernatural stuff, though. Seriously, the Lepricorn?"
Mabel fiddled with her hair. "But you can at least think that you might have forgotten the whole summer?"
"Yes, I guess..." Dipper rubbed his forehead.
"Then I'll convince you it's true!" Mabel said. "With all the weird stuff happening in Gravity Falls, that should be easy!"
"Kids?" Grunkle Stan shouted once more. "I didn't really get an answer on the forging. I know last time didn't go so good, but this time there'll be no county jails, I swear! Probably."
"Like that!" Mabel grinned. "See, you don't remember how cold the county jail was."
"Okay... but if I really have forgotten the whole summer, what am I gonna say to Great Uncle Stan?"
"Just play it cool, bro bro. We'll have your memories back in no time, there's no reason to make him worried!"
"Still waiting for an answer, kids! I'll just, take that silence as a yes? Start cutting out rectangles, you know, for all the money we're going to forge?"
Dipper frowned. "Should we call the police? Or our parents?"
"Whaaat? No way, it'll be fun. Coming, Grunkle Stan!"
"But he's literally forging-"
Mabel shoved a finger up to her brother's lips. "Shhh shhh, I said play it cool."
"Literally forging money-"
"Play it cool."
"That's a felony-"
"Shh, I said play it cool."
"Okay, fine." Dipper crossed his arms. "I guess we'll play it cool and... go forge money with our Great Uncle Stan. Am I saying this right?"
Mabel stashed the journal back underneath Dipper's bed "No you're not. It's Grunkle Stan, not Great Uncle Stan. That just sounds weird!"
