"Mabel, hurry! Shut it down!"
        Mabel cast a fearful glance toward her brother, who was floating near the ceiling, clinging to a wooden beam for dear life. Then she began climbing down the wire her foot had snagged on towards the shutdown button.
        Gravity was gone, sucked away by the strange futuristic machine behind her. The world had literally been turned upside down. Loose pebbles, pipes, and wooden boards drifted aimlessly through the air, no longer anchored to the earth.
        Finally reaching the shutdown switch, Mabel raised her fist over the glowing red button. But as she did, her great-uncle Stan shouted to her.
        "Mabel, Mabel, wait! Stop!" Suddenly, he was tackled in midair.
        "Soos, what are you doing?! I gave you an order!" he shouted, pounding the handyman with his fist.
        "Sorry, Mr. Pines-if that is your real name. But I have a new mission now: protecting these kids!"
        "Soos, you idiot! Let me go!" Just then, Dipper pushed off of the wall and tackled Stan as well. The old man grabbed him, trying to push him away.
        Mabel looked back and forth between her brother and her uncle. What was she supposed to do? In a matter of minutes, the weight of the entire world had been thrust upon her shoulders. Why her? Why did she have to be the one to make this decision?
        Struggling in Stan's grip, Dipper shouted, "Press the red button! Shut it down!"
        "No, you can't! You've gotta trust me!" her uncle pleaded.
        How could she choose?! This was tearing her apart! She loved them both so much, but who was she supposed to trust this time? Mabel couldn't take it anymore. She felt tears welling up in her eyes, slipping out and floating away.
        "Grunkle Stan..." she said, sobbing, "I don't even know...i-if you're my grunkle."
        Mabel's crying seemed to cut through every other noise, even the whirring and crackling coming from the portal. When they heard it, the others stopped fighting for a moment, watching her tears drift up and away.
        Mabel sniffled. "I wanna believe you, but..."
        Stan immediately saw an opening. "Then listen to me! Remember this morning, when I said I wanted to tell you guys something?"
  Suddenly, a computerized voice rang out. "T-minus 20 seconds." With a bright flash, the portal released a burst of energy that knocked Dipper, Stan, and Soos back against the wall.
        No, this was getting too dangerous, she decided. She had to shut it down. She decisively raised a hand over the shutdown button, but Stan spoke again.
        "I just wanted to say that you're gonna hear some bad things about me, and some of 'em are true. But trust me, everything I've worked for, everything I care about, it's all for this family!"
        "Mabel, what if he's lying?! This thing could destroy the universe! Listen to your head!" Dipper cried out. Mabel looked over at him. Her brother had always been there for her. He had always done what was best for her. Over the years, he had sacrificed so much to make her happy.
        "Look into my eyes, Mabel!" Stan shouted desperately. "Do you really think I'm a bad guy?!" Suddenly, memories began to surface in Mabel's mind.
         Stan shouting, "Alright, you undead jerks! You ready to die twice?!" as he bravely fought off the zombies that had infested the shack, giving Dipper and Mabel time to run to the attic. Stan saying, "Hey, uh, how about each of you, uh, take one item from the gift shop, on the house," after they had come back in from battling the gnomes on their first day in Gravity Falls.
         Stan giving her a sticker that said "u da best" and saying "Knock her dead, kid," before her golf tournament with Pacifica. Stan riding on the pterodactyl with Waddles strapped to his chest, punching it in the face and screaming, "I STABBETH THEE!"
          No. She didn't think he was a bad guy. She loved him with all her heart, and she knew he loved her back, even if he didn't always say it. She trusted him.
          "He's lying!" Dipper screamed. "SHUT IT DOWN, NOW!"
          Mabel looked at the swirling portal behind her. She could see the void that lay beyond the flashing colors and the crackling lightning. At first it had looked so dark and empty...but now that she looked closely she could see that it was filled with thousands of stars, little twinkling lights filling up the shadows. She let those tiny lights swell and grow inside of her, filling her with the courage she needed for what she was about to do.
           Then she looked up at her great-uncle. The swirling colors reflected in his glasses, creating a rainbow that spun around and around inside the lenses. He looked at her pleadingly, an expression she had never seen on him before.
            "Mabel, please!"
            She had never heard Stan, high and mighty Grunkle Stan, say please. Not willingly, at least. She saw so many unsaid things, deeply-buried emotions, flashing through his eyes. Desperation, determination, hope...and love.
"10...9...8.." the computer counted.
In that moment, Mabel made her decision. Then she said the five words that would change their lives forever.
            "Grunkle Stan..."
           "6...5...4..."
            "I trust you." She let go of the button and let herself float up into the air.
A spear of ice stabbed through her heart when she saw the look of absolute betrayal on her brother's face. Then his expression became angry.
         "Mabel, are you CRAZY?! We're all gonna-"
           "...1."
They all screamed as the portal flashed as bright as the sun. The light enveloped everything, taking away all of the world's color until until there was nothing left but white. Then the futuristic machine exploded.
But Mabel barely heard it. The bright light rushed through her, and somehow she felt peaceful. It lifted her up, carrying her away from all of her problems and troubles. Then suddenly the whiteness disappeared, and everything went black.

---------------------------------------------

     When Mabel came to, the basement was in ruins. The portal lay on the ground, sparking and crackling. Wooden planks and other loose debris were strewn across the floor, and a light shower of dust floated through the air.
     Mabel slowly got to her feet, her stomach churning as though she had just eaten a whole packet of Smile Dip. To her great relief, she saw the others getting up as well, rubbing their heads and groaning.
     Then a cloaked figure emerged from the portal, planting one foot on a chunk of ceiling that had fallen when the portal exploded. His face was concealed by a pair of goggles, and there was something that looked like a large gun strapped across his back. He looked like a survivor of some ruinous apocalypse.
The man slowly stepped towards Journal 1, which was now on the ground. He bent and rested a hand on the battered red cover, as if to convince himself that it was real. That's when Mabel saw it.
His hands...his hands each had six fingers.
The man now stood, placing Journal 1 into one of the many pockets inside of his cloak. So many questions filled Mabel's brain, all clamoring for attention: Who was this man? Where did he come from? Why did Stan have this huge portal? And why did he keep it a secret from them?
Dipper stared at the six-fingered man, shaking his head in disbelief.
"What...who is that?"
     "The author of the journals..." Stan intoned. The mysterious stranger then pulled back his hood and removed his goggles.
Mabel suddenly felt as though her heart had stopped. This man looked like...Stan.
          "My brother."

The idea for this story came into my head one day because I was wondering what was going on in poor Mabel's head during this whole scene with the portal, and then I thought, Hey, why not write a fanfiction about it?

Update: I was originally planning to continue this, but now I've decided not to. Sorry...