Dipper wakes up and screams.
Mabel, as Mr. Upside-Downington, "Mornin', Dipper, guess who!"
"Oh, what joy. If it isn't Mr. Upside-Downington. How long's it been? Third grade, maybe?" Dipper asked.
Mabel smiled, "That's right. And I'm here to deliver you an upside-downington-tastic message!"
"Is it the message that we're getting too old for this sort of thing?" Dipper asked.
Mabel , using her normal voice, "Um, kinda, actually. It's that we are exactly one week away from our 13th birthday!"
"Whoa! Our birthday's coming up already?" Dipper gasped, "Soon we're gonna be actual teenagers!"
Mabel cheered, "Finally! I can stop reading preteen magazines and start reading post-preteen magazines."
"PG-13 movies, here I come!" Dipper shouted.
Mabel smiled, "And just one more year until high school. High school, Dipper! Where girls become women and they teach us stuff about... She turns Dipper around and whispered, "You know what."
Dipper smiled, "Trigonometry?"
"Oh yeah, baby!" Mabel cheered.
Stan and Soos enter the room.
Stan smiled, "That's not the only good news coming up! In one week my senior citizen's ponytail kit is coming in the mail. I'm...I'm kinda going through some things."
"In one week, my grandma is finally letting me eat crackers on my bed! The future is coming for us all, dudes," Soos smiled.
Stan grinned, "The future."
"The future!" Dipper shouted.
Mabel shouted, "The future!"
Dipper laughed, "I'm sorry, I can't take you seriously with that face on your chin."
Mabel , as Mr. Upside-Downington, "What face, Dipper?"
"You're-You're doing the voice so you obviously know what I'm talking about-" He laughed.
Mabel grinned, "Bi bon't bnow bhat bou're balking about."
Dipper and Mabel both laugh.
"There is something wrong with you," Dipper laughed.
Mabel smiled, "There's something wrong with both of us."
Stan, Soos, Mabel, and Dipper leave the room, Will being the only one left.
Will frowned, "... 'a day will come in the future when everything you care about will change'... I shouldn't be worrying... we have the rift safe, and... the shack has the barrier around it, even though... it kind of affects me, not surprising, but still... I can't help, but wonder... what day will that be? He only has a week to do this, because Mabel and Dipper are going to be involved, I just know it... but how? ...and when?"
"Alright, party planners. In one week we become teenagers, and our summer vacation winds to an end. So we need to throw the greatest party of all time! I'm talking piñatas with tinier piñatas inside!" Mabel shouted.
Soos pours tiny piñatas into bigger piñatas, "Boom, dreams comin' true!"
"I'm talking inviting everyone in town. Let's see, where do we stand with the gnomes?" Mabel asked.
"Not so fast, goofus and girl-goofus." Stan walks into the room, "After that zombie incident, no one's throwing another party at my house."
Mabel frowned, "But Grunkle Stan, we need some roof to raise."
"Dude, you could rent out the Gravity Falls High School gym, and have your party there. That place is empty all summer long," Soos suggested.
Mabel smiled, "The gym's a great idea, Soos. To the high school!"
The entire house quakes, startling everyone.
"I'll just be a sec." Dipper runs into Ford's room, with Will following after him, "Great Uncle Ford, are you okay?"
Ford, wiping off his face, which is smoking, with a towel, "Oh yes, I'm fine. I just said that to make sure you'd come in here quickly."
"But your face is on fire," Dipper pointed out.
Ford nodded, "Yes, it's much faster than shaving. Now, listen, Dipper. I have a very important mission, and you are the only one who can help me." He pulls out the rift, "Remember the rift in dimensional space-time I showed you? It's cracking." He points at the crack, "This is what Bill has been waiting for. If it breaks, it will cause reality as we know it to completely unravel. A hypothetical and catastrophic event I call Weirdmageddon."
Will frowned, looking at the crack, "... So... if it fully breaks... it'll happen... and..."
"It?" Dipper and Ford stare at him.
Dipper gasped, "Wait... you were referring to something a few weeks ago, saying... it was going to happen in a few weeks... do you mean this?"
"... unfortunately, yes... and I can't exactly fix... this," Will looks over at the rift.
Dipper stares at a blackboard Ford has drawn up, detailing the finer points of Weirdmageddon.
"Bill is out there, and he'd use any trick, from deception to outright possession, to make this happen. But for the sake of humanity, we mustn't let it," Ford sighed.
Dipper frowned, "What do we do?"
"We patch the rift. I'll explain on the way," Ford locks the rift in a protective case.
Dipper looks at Will, "Wait, what about Mabel? ... and Will?"
Mabel, standing in the doorway, "It's okay, Dipper. You should totally go with Grunkle Ford to save the world or whatever."
"Are you sure?" Dipper asked.
Mabel nodded, "We're going to be doing birthday junk all week. Plus, I packed us walky-talkies. Here's one for my party mission, and one for your smarty mission."
Ford clears his throat, "I did mention that the fate of the universe is at stake, didn't I? Hurry, we haven't much time."
"Okay, Dipper. It's your first big mission with Ford. A chance to prove yourself. Don't mess this up." He runs and hits the wall, "Ow! Ah, heh heh, I'm alright." He laughs, then runs out and trips, "Ahh!"
Nate and Lee are messing with the Gravity Falls High School sign, which says "SAWDUST INHALATION DRILL- 8:00. GO FIGHTING BEAVERS."
Mabel, Will, and Soos walk inside to see the gym filled with students.
Mabel gasped, "Whoa, Soos, I thought you said this place was empty."
"My dawgs, what up?" Wendy asked.
Mabel was confused, "Wendy, what are you doing here?"
Wendy groaned, "Ugh, high school registration."
"Ooh! You know I'm only a year away from high school myself. Would you say your experience is more rom-com, or wacky romp?" Mabel asked.
Wendy grumbled, "More like teen horror movie. High school is the worst. Classes get super hard, your body just flat out turns against you, and worst of all, everybody hates you."
"Why aren't they singing about following their dreams? TV taught me that high school was like some sort of musical," Mabel smiled.
Wendy frowned, "TV lied, man! If you could avoid growing up, do it. I'd give anything to be 12 again. Anyway, what are you guys doing here?"
"Oh, just looking for a place to have my 13th birthday party..." Mabel looked down.
Teacher smiled, "Wendy...Borduroy? I-I mean Corduroy?"
All the students laugh at Wendy.
Wendy blushes red, "See what I mean?" She asked, before she walks to teacher.
Mabel exits the gym, "Master Mabel to Dippidy Dog. We can have our party at the gym, but we gotta talk about high school. Starting to think it might not be the awesome future we were expecting. Over."
Dipper, on the walkie talkie, "I'm going through a bad patch, Mabel. We'll talk when I get back."
"Dipper? Come in, come in?" Mabel asked.
Soos smiled, "Hey, I know what'll make you feel better. Let's deliver some invites to your friends, huh?"
"Yeah!" Mabel cheered.
Mabel and Soos drive away. Mabel finds that the sign now reads "NO ESCAPE."
Dipper, to the walkie talkie, "Mabel? Mabel, you there? Ugh."
"Listen, Dipper. In order to seal the rift for good, it's going to take an adhesive stronger than anything on earth. Something...extraterrestrial in origin," Ford explained.
Dipper frowned, "W-What do you mean?"
"Dipper, look at the peculiar shape made by those cliffs. Does it remind you of anything?" Ford asked.
Dipper hummed in thought, "Hmm..."
Ford jingles his UFO key chain and holds it up over the cliffs.
Dipper gasps quietly, "Shut. up."
"According to my research, the entire valley of Gravity Falls was formed when an extraterrestrial object crash-landed here millions of years ago. Did this craft cause the town's strange properties? Or, did the town's strange properties attract the craft? The answer is still unknown," Ford explained.
Dipper frowned, "But, that's crazy! Where did the saucer go?"
"Sometimes the strangest things in the world are right under our noses." Ford pushes rock away, revealing underground entrance, "And our feet, in this particular instance. Now you might wanna stand back. This magnet gun can rip the fillings out of a man's mouth from 100 feet."
Dipper backs away a few steps as Ford detaches the opening, "Whoa!"
"I used to raid this thing for parts for years. Where do you think I got the materials to build my portal?" Ford asked.
Dipper gasped, "You...I...words... not working for mouth."
"Now come. Take this," Ford throws Dipper a magnet gun.
Dipper, scrambling to catch the magnet gun, "Whoa, whoa!"
"Don't worry, I've been down here countless times; all the aliens have been dead for millions of years." Ford starts climbing down but then pops up, "Probably."
Dipper takes a deep breath and heads down the entrance.
Dipper gasped, "I can't believe there's been a giant UFO under the town this whole time."
"I wish my mind could be where yours is right now, Dipper. When confirmation of extraterrestrials still had that punch. Now it's just sort of "eh." McGucket and I used to come down here all the time to raid their tech and study their language," Ford explained.
"This is so cool!" Dipper takes a selfie with some of the alien symbols and laughs.
"The substance we need to seal the rift is an alien adhesive. Strong enough to keep the hull of a spacecraft together. Just one dollop of this adhesive should be enough to seal a crack in space-time. Also, if it touches you it will seal up all the orifices in your face," so try to avoid that. Now, use your magnet gun and follow me," He uses magnet gun to climb down a pillar.
Dipper releases a deep breath, "Okay. Just turn on magnet, leap down hole. Turn on..." He fiddles with gun, "C'mon already." gun whirs to life, "Magnet." He grunts as he jumps, "Ah!" He crashes onto the ceiling, "A little help?"
Mabel knocks on Grenda's front door.
Grenda smiled, "Oh hi, Mabel! You're just in time for our 1 o'clock boy talk."
"If you think that's good...Boom! Me and Dipper's 13th birthday jam!" Mabel smiled.
Grenda frowned, "Aw, man. Your birthday's on the last day of summer? I'm not gonna be here."
"What?" Mabel asked.
Grenda explained, "Marius is flying me out to Austria to hang out in his castle or whatever that week. He's so clingy!"
"You're gonna be out of town for my birthday? But at least you can come, right, Candy?" Mabel asked.
Candy shook her head, "Sorry, Mabel. My parents send me to music camp this time of year. There is no escape from music camp."
"So neither of you are gonna be at my birthday party? And you won't be able to wish me goodbye at the end of the summer?" Mabel asked, "I think I need to radio for emotional back-up. Dipper, please come in. Our party mission is going down in flames. Over."
There is static on the walkie talkie, and she sighs.
Ford smiled, "This is their storage facility. This place would've been heavily guarded, but now everything's defunct. Go ahead, flip any switch. They've all been busted for millions of years."
Dipper pushes a button and it causes a petting zoo to fall down a hole.
"The glue should be around here somewhere, so keep your eyes peeled. Dipper, let me ask you something. Have you thought much about your future?" Ford asked.
Dipper shrugged, "No, not really. I mean, beyond graduating high school with a high GPA so I can get accepted to a good technical college with a photography and media production minor to start my own ghost hunting show."
"Ha, heh heh! It's like talking to a younger version of myself. If you're so sure of what you want out of life, why wait? Why put up with the drudgery of school?" Ford asked.
Dipper laughed, "Heh. Trust me, I'd love to fast-forward the whole thing, but it's not like I have a choice."
"Dipper, I've been thinking. I'm getting too old to investigate Gravity Falls on my own. I need to train an apprentice to help me fight monsters, solve mysteries, and protect this town. And I think I'd-I'd like to keep it in the family," Ford smiled.
Dipper gasped, "What are you saying?"
"I've read your additions to my journal and I'm impressed with your potential. What would you say to staying in Gravity Falls after the summer ends and becoming my apprentice?" Ford asked.
Dipper frowned, "W-what about school?"
"Dipper, I have 12 PhDs. Your parents would be thrilled I could give you such an advanced education," Ford smiled.
Dipper sighed, "There's also Mabel. She'd be all alone in California."
"Mabel will be fine on her own. She has a magnetic personality. I watched her become pen pals with the pizza delivery man in the 60 seconds he was at the door," Ford smiled.
Dipper frowned, "Gosh, we've never really been apart before."
"And isn't it suffocating? Dipper, can you honestly tell me you never felt like you were meant for something more?" Ford asked.
Dipper shakes his head, "I-I dunno. Sounds like a dream come true, but I'm not sure I have what it takes. I was tricked by Bill, I was wrong about Stan's portal. Heck, I can't even operate this magnet gun right." He turns on the magnet gun and it sucks up a piece of metal. As Dipper tries to get it free, something pink seeps out of it.
"Ha! Yes! Dipper, you've found the adhesive!" Ford shouted.
Dipper gasped, "I did?!"
"Hoho, you really did it, kid. Huddle in, let's get a picture of this," He hears something and holds up gun.
Dipper whispered, "Uh, Grunkle Ford, you said everything in here is dead, right?"
"Yes. Unless somehow we've reactivated the-" He gasped, "security system!"
The security droids emerge.
Mabel is in the attic looking at scrapbooks.
Mabel sighed.
Stan walked in, followed by Will, "Hey, everything all right, pumpkin?"
"Just can't believe the summer's almost over. And now that I know how awful high school's going to be, I'm in no hurry to start that train wreck," Mabel frowned.
Stan puts his arm around her shoulder, "Ah, nobody likes gettin' older. But just because you're growing doesn't mean you have to grow up, you know? I mean, look at me. I'm pushin' seventy and I still eat ice cream for dinner."
Mabel frowned, "But I don't wanna say goodbye to Gravity Falls."
"Hey, at least whatever happens after this summer, you'll still have your brother along with you through thick and thin. Not everyone can say that, you know," He noogies her and leaves.
Will looked down, hearing Stan's words.
Mabel smiled, "Yeah, at least when I go home I always have Dipper." She picks up a picture of Dipper, "Good ol', reliable ol'-"
Her walkie-talkie crackles.
"Are you okay?"
"I'm fine."
"Let's get you out of there."
"Listen to me, Dipper: this town is a magnet for things that are special. And that includes you and me. It brought both of us here for a purpose! Stay here with me, Dipper. Become my apprentice. Don't let anyone hold you-" Ford coughs.
Dipper offers him his hand, "I'll do it; I'm gonna stay."
"Excellent." Ford grabs Dipper's hand and climbs out of the ditch, "Now who wants to save the world, apprentice?"
Dipper and Ford walk away laughing.
Dipper's walkie-talkie makes static noises.
Dipper comes in, "Mabel! I just had the best day of my life! UFOs are real and there's one under the town and I saved Great Uncle Ford's life and- and..." He sees that Mabel is lying on her bed with her back to him, unmoving, "Hey, are you okay?l
Mabel frowned, "Tell me it's not true, Dipper. Tell me you were joking." She holds up the walkie-talkie, which emits static, "Ford's apprentice? Seriously?"
"Look, I was thinking and... this is a huge opportunity for me," Dipper smiled.
Mabel starts crying, "Well it's a horrible opportunity for me! I had the worst day of my life! When we turn thirteen, the summer ends, and I have to leave everything behind. You're the only person I can count on and now you're leaving me too!?"
"Look, I've been thinking about it. I won't be gone forever, okay? I'll still visit you at home, and we'll chat online; we'll make it work," Dipper smiled.
Mabel frowned, "I don't want it to work. I just wish summer could last forever."
Dipper walks over to her and puts his arm on her, "But it can't, Mabel. Look, things aren't gonna stay frozen this way. It's part of growing up. Things change. Summer ends."
Mabel yells and runs away.
Dipper falls over, as he was leaning on her, "Mabel, wait! I didn't mean it like that! Mabel, come back!"
"... 'a day... will come in the future when everything you care about will change'... Dipper..." Will looks up at him.
Dipper stares at him, "What?"
"... I think that's today... right now..." Will frowned.
Dipper looks at the door, "I... I need to go see Ford."
"... I'll go try to find Mabel."
Mabel runs into the woods crying. She sits under a tree, digs through the backpack, "Only party chocolate can cheer me up now." She holds up a notebook, "Nerd books?" She holds up pens, "Chewed up pens? Ugh, wrong backpack." She pushes the backpack away, "It's not fair... I just wish summer could last forever." She pulls her sweater over herself.
Blendin calls out, "That might be possible!"
"Sweatertown is not accepting incoming calls right now..." Mabel frowned.
Blendin shuddered, "M-M-M-Mabel, it's me."
"What? Who said that?" Mabel asked.
Blendin walks up to her, adjusting his camoflauge suit, "I-I-I can help."
"The time travel guy? What are you doing here?" Mabel asked.
Blendin looks at her, "You said you don't want summer to end, right? D-did-did I hear that right?"
"Yeah... why are you asking?" Mabel asked.
Blendin smiled, "Look, maybe it's against the rules, but you once did a favor for me, so I thought I could help you out. It's called a time bubble, and it prevents time from going forward. Summer in Gravity Falls can last as long as you want it to!"
"R-Really? But how does it work?" Mabel asked, wiping her tears.
Blendin smiled, "I just need you to get a little gizmo for me from your uncle. It's something small. He won't even know it's missing."
"Huh. Maybe Dipper has something like that in his nerd-bag..."
Ford stares at Dipper, "Let me guess: Mabel didn't take it well?"
"I don't know, maybe I'm making the wrong decision. I need to think about this," Dipper sighed.
Ford frowned, "Dipper, right now we need to focus on the mission. Now come on, I've got the glue; hand me the rift and let's make history."
Dipper reaches into his bag and pulls out a birthday flyer, "What? Oh no! The RIFT!"
Mabel pulls the rift out of the backpack, "Huh. That's... odd. This it?"
"Yes, that's it! Just hand it over and I'll do my thing. Unless you're ready to leave Gravity Falls," Blendin grinned.
Mabel whispered, "Just a little more summer."
"Mabel, wait!" Will shouted, walking over to them.
Mabel jumped, causing the rift to fall on to the floor and break.
Will looks over at "Blendin", "You..."
"Huh?" Mabel asked.
Will looked down, "Mabel... we have to go, now..."
"Why? What's going on?" Mabel asked.
Will shakes his head, "Mabel, we have to go! Now!"
"... okay..." Mabel follows him to the shack.
Townspeople look on, worried. Wind blows. Dipper and Ford run out of the Mystery Shack.
"What's going on?! What is that?!" Dipper asked.
Will runs over to them with Mabel, "It broke... oh, we're in trouble now..."
"Will... would the rift give you any... extra abilities?" Ford asked.
Will bit his lip, "I don't know... but we have to get to the shack. It's the only safe place to be right now."