Piedmont, 2017

"Dipper, Mabel! Come here!" a lady calls, her voice stretching throughout the house. Two pairs of feet are heard coming down stairs before two twins appear in the room.

"Yes, mom?" Mabel asks, her brother just as curious to find out what was going on.

"I just heard that your uncles will be back in Gravity Falls for the summer, how would you like to go stay with them again?" their mother asks.

The twins start speaking over each other in their excitement, their answer a resounding yes. Their mother chuckles at their eagerness and smiles.

"I'll let them know you're coming then," she says, "You'll leave at the end of the week, make sure you're all packed by then".

The twins rush back up the stairs to their respective rooms to start getting their things ready for when they leave in four days.

Gravity Falls, 2017
Four days later

A bus pulls into the Gravity Falls Bus Station and opens it's doors. "Gravity Falls, Oregon," the bus driver calls.

Dipper and Mabel stand up and grab their bags. They excitedly hop off the bus, Mabel calling out a quick 'thank you' to the bus driver while Dipper looks around for their uncles. He quickly spots the two men and runs over to them, his sister in tow.

"Grunkle Stan!! Grunkle Ford!!" they call out in unison. The men in question smile as they embrace the twins in a hug.

"Welcome back kids," Stan says warmly.

"Look at you both, you've grown so much I almost didn't recognise you," Ford says with a chuckle. It's true, the twins changed a lot in the five years since their first summer in Gravity Falls.

Mabel no longer has braces and her hair is shorter, falling only slightly past her shoulders. She wears capris with fringed edges and slight rips on the knees, flowers are embroidered along the sides of the legs. Her shoes are stylish ankle boots with a one inch wedge. She still wears her sweaters but they are styled so that one shoulder is exposed, you can see a tank top peeking out underneath. On one wrist is a few wristbands, on the other lies a charm bracelet with a multitude of charms. She has a chain with a shooting star pendant around her neck and star themed earrings.

Dipper is a few inches taller than her and she's conceded to him being the alfa-twin. His hair is shorter on the sides and slightly spiked up on the top, a little bit peeking out from under the hat that Wendy gave him covers his birthmark. He dons a red plaid flannel with a navy blue hoodie zipped half-way over it. He wears dark blue-almost black skinny jeans and has black converse. His right ear is pierced with a plain, black, circular earring sitting inside. On his forearm lies a blue pine tree tattoo.

"So what brings you back to Gravity Falls?" Dipper asks as they climb in Stans car.

"Yeah, we thought you were traveling the world and junk," Mabel adds.

"You would be correct in that assumption," Ford answers, "We were investigating anomalies all across the globe when I noticed something peculiar. For some reason, the number of anomalies happening monthly in Gravity Falls decreased. Somehow, the Gravity Falls weirdness has been disappearing so we decided to come investigate."

"What?! But the weirdness is what makes Gravity Falls Gravity Falls! It can't go away!" Dipper exclaims shocked. Mabel nods in agreement.

"Poindexter here said almost the exact same thing. Said we needed to come find out what's causing this and, if we can, stop it," Stan says.

"Well we're with you!" Mabel cheers.

"We're ready to help every step of the way," Dipper adds determinedly.

"I'm glad to hear that, we might need it," Ford says.

They soon arrive at the shack. Soos and Melody, who have been doing a great job of running the shack in the Pines' absence, coming out to help them with their bags. They learn that Soos and Melody are engaged now and they got their own house in the town, not wanting to have disturbed the Pines' things when they came back.

The twins feel a wave of nostalgia crash over them as they enter the attic and unpack their things. They look around the room fondly and take a moment to indulge in their memories.

"Remember when I made that magic flashlight so I could be taller than you?" Dipper says with a laugh.

"Yeah, and it didn't even matter cause you're the taller one now. Remember when we switched bodies and you got stuck in a sleepover?" Mabel replies.

"Oh god, don't remind me. That was awful," Dipper complains.

Before they can reminisce anymore, they hear their grunkles calling them down for lunch. They head down the stairs with excitement.

"C'mon kids, we're going to Greasy's Diner for lunch. Some of your friends will be meeting us there to catch up." Stan says. The teens smile happily and climb into the back seat of the car. Ford climbs into the driver's seat and Stan gets in the passenger seat. They then drive off, excited to see their friends again and anxious to start investigating the lack of Gravity Falls weirdness.

???, 2017

Bill drifts through the dark emptiness that has trapped him for years. He and the demon known as Cipher have been stuck there together for the last five years with only each other as company or entertainment. Suddenly the demon becomes a lot more alert, Bill sits up straighter as well.

"Something's wrong," Cipher says.

"I feel it too," Bill agrees.

The two look at each other with worry written on their faces. They look around anxiously, waiting for something to happen, but nothing does. Left in suspense, the two sit in silence and prepare for the worst.