"Well, kid, it's been real fun. But I've gone people to turn, and places to burn."

Dipper's footfalls are the only thing he can hear now. Thundering in his ears, one after another after another, as he sprints towards the voice he just heard echoing through the trees. 'I know that voice.', Dipper thinks to himself, scanning his memory for it. He doesn't know whose voice it is, but he recalls the fear it summons up when he hears it. He pushes himself, sprinting as hard as he can towards the sound. As he breaks through the wood into a clearing, the sight that greets him stops him dead in his tracks.

Bill Cipher was hovering in the air at the far edge of the clearing; a single eye glaring down at the forest floor. Dipper's feet were frozen into place. 'How? How is this possible? The rupture between dimensions was sealed! We sealed it! I sealed it!' And, yet, here he was. Bill had somehow managed to free himself into their world. Dipper started to try to formulate a plan. Should he get help? Great Uncle Stanford was back at the cabin. It wouldn't be difficult to run back and alert everyone to what was going on. That was the smartest plan, Dipper thought. They could all face this together.

As he began to turn back towards the trees, he suddenly remembered that he had heard Bill's voice. Who was he talking to? Dipper turned back around and saw Bill was still glaring at the ground, eye transfixed on a single figure cowering against the base of a nearby tree. The color drained from his face as his eyes fell on a bright purple sweater with a bedazzled unicorn on the front. Mabel was staring up at Bill, her hands outstretched in an effort to somehow force him to stay back. Dipper knew better. If Bill had somehow found a way past the barrier between dimensions, he wasn't going to stop now. Dipper had to help Mabel. No other plan mattered now. He began to sprint.

"Show's over, kid!" Bill said. "We had a good run! We really did. But nothing lasts forever! So long, Shooting Star!" He raised his hand and pointed a single, black finger at Mabel. She closed her eyes as tight as she could, bracing herself for whatever was about to happen next. Dipper was so close, if he could just reach Mable in time...

A sound the likes of which Dipper had never heard erupted through the clearing, and then everything was silent. Dipper couldn't even the sound of his own feet thundering into the earth as he ran with all his might. Time seemed to slow down as he raced towards them. Or, maybe, time had actually slowed down. With Bill involved, he couldn't know for sure. A strange light appeared at the end of Bill's finger. As Dipper looked at it, it was as though he was looking into the deepest reaches of the universe itself. He was almost there, and he could see Mabel's face twisted into a scream that nobody could hear. He pushed himself as hard as he could, diving towards them. The light at Bill's fingertip erupted towards Mabel.

Dipper wasn't fast enough to get in between them. There was a terrifying flash of light and then, Mabel was gone. His legs gave out beneath him as he skidded to a halt in the cold grass, sliding on his knees. He saw burnt patches of her sweater floating lazily towards the ground. He felt his heart shattering into pieces, Bill shrieking with mad laughter. She was gone. His thoughts were chaos, unable to make sense of it. He would never hold her hand again. Never hear her laughter. She would never 'boop' his nose. He felt a vast emptiness in the universe. Mabel was a part of him, in so many ways. Some he had never even been able to comprehend until now. But it was too late for that. He couldn't help her now. Bill rounded on him.

Bill raised his hand, again tapping into whatever horrible power it was that had scorched Mable out of existence. "Don't worry," he heard, vaguely. Bill was calling out to him, his voice sickly with the sound of his own glee. "you won't have time to worry about any of this. I have much bigger fish to fry, kid!" Bill brought his aim to bear on Dipper, that same sickening sound filling his ears. He could see the beam more clearly now, as it bore itself down upon him; stars, nebulae, galaxies, all screaming towards him. He felt it wash over him as his body went cold. It felt as though his brain were being forced to expand, as if Bill was pumping every last bit the universe into his mind. Images of places he'd never been and people he'd never met careened through his thoughts. No sooner did one appear than it was gone, replaced by another one. And then, suddenly, he felt his legs give way and his vision blurred as he faded away into nothingness.

"Touché, Pine tree."

The smell of burning pancakes drifted lazily through the room. Dipper's opened an eye, peering around the Twins' moldy attic bedroom at the Mystery Shack. 'The Mystery Shack?', Dipper thought. He was wide awake now, sitting up in his old bed and staring around the room. Mabel wasn't there. Had he been too late? Had he passed out from whatever it was that Bill had done to him? He could hear someone downstairs, which explained the smell of bad cooking. Suddenly, he could hear footsteps crashing up the stairs. The door sprung open, and a blur of bright green came hurtling towards him.

"Finally up! We thought you were gonna sleep all day, bro-bro!"

It was Mabel. She had perched herself at the foot of the bed, beaming at him. She looked like she usually does, her hair tied back in a red ribbon, wearing her favorite turquoise sweater. "I was worried you were going to sleep through our birthday!" Dipper was confused.. Their birthday had been two weeks ago. They had gone walking through the woods the day before, and he had discovered an old cave full of some of the shiniest stones he'd ever seen in his life. He smiled briefly as he thought about it. He had stuffed his pockets full of them, and had decided to make something with them as a birthday present to Mabel. They'd gotten back so late that he'd went to bed in his clothes and woke up the next morning with the stones still lining his pockets.

Dipper's hand navigated absent-mindedly to his vest pocket and, to his surprise, it found the stones there. He looked down at himself, still wearing the same clothes as he had worn on their hike through the cave. A wave of relief washed over him. 'It was just a dream.' Bill was still contained within the dreamscape, and Gravity Falls was safe. He looked up at Mabel, who was chuckling at him. "You slept in your clothes again, ya big dork!" she teased. Her sing-song voice was music to his ears. 'Everything's fine. It's all fine.'

The twins made their way downstairs and into the kitchen, where Gruncle Stan stood at the stove flipping blackened "Stancakes" into the air, muttering curses under his breath. Dipper watched the familiar scene, glad that the horrors of his dream had been washed away, replaced with the simplicity of reality. It was good to have a routine. How many times had this scene played out in his life? Stan at the stove, making a mess of breakfast, Mabel sitting at the kitchen table crafting who know what out of glitter and pipe cleaners. It was all so familiar. So every day. Suddenly, a loud crash jerked Dipper out of his thoughts.

Stan's skillet had become detached from its handle during an especially vigorous flip, and had launched itself through the kitchen window and into the yard. Mabel howled, throwing her head back with laughter and pointing. Without knowing why, Dipper started moving towards her. Just as he got within arm's reach, her chair began to tip over backward. Dipper put a hand on the back of the chair and push, firmly planting all four feet on the old linoleum beneath. "Nice catch, Dip!" Mabel said, smiling. She put her hands together and batted her eyelashes, pretending to be feel feint. "My hero!"

Dipper didn't understand. He felt like she her chair was going to tip before it even had. And that whole thing with the skillet seemed strangely familiar, too. 'Déjà vu,' he thought, and swept it aside in his mind. He couldn't remember Gruncle Stan ever hurling a frying pan into the yard before, but it must have happened. It was too specific a thing to slightly recall. "Well," Mabel said, beginning to stand. "I want to start setting up for the big bash! You don't turn 17 every year, ya know!" She bounced out of the room, skipping towards the attic stairs. This was all eerily like Dipper's dream. Or, at least, he thought it was. He couldn't be sure, as it had covered two weeks of his life. 'A lot can happen in two weeks.' he thought. He scoured his mind to try and recall anything specific that had happened over the last two weeks, suddenly recalling a terrible joke Gruncle Stan had told him about a pool table.

Dipper turned as Gruncle Stan came through the door, holding between his oven-mitted hands the remnants of what was to be their breakfast. 'Only one way to find out,' he thought. "So, Gruncle Stan," he began. "Hear any good jokes lately?" Stan dropped he skillet into the sink and turned towards his nephew. "Sure I have!" he bellowed. "Wait, how old are you?" he asked, lifting his fez and scratching his temple. Dipper blinked. "17." He said. Stan placed the Fez back on his head, frowning. "Your old man would blow a gasket if I told you that one." He said, thinking aloud. "Oh, wait! I've got one." He rubbed his hands together, as if he was about to bestow upon the world the most wonderful of gifts. "What's green, has four legs, and would kill you if it fell out of a tree?" Dipper felt his heart stop. "Uh…a pool table…" he said, grimly. Stan frowned again. "You read too much, kid. Go outside!"

Stan turned back a round to the sink and began washing the skillet as Dipper sprinted up the stairs. He could hear Stan repeating the punchline and cackling to himself as he reached the top of the stairs. Here was Mabel, sitting on her bed, bedazzling her old birthday sweater. She'd been adding to it every year since they were 10, pulling off the old number and adding in the new. Dipper had a sinking feeling in his gut. Mabel jumped up and brandished her handiwork at him. "Hey Dipper, wanna see what I added this year? I jazzed up the front and-" Dipper took a step forward, cutting her off with a wave of his hand. "…Let me guess, you bedazzled 'Alpha Twin' on the back?" Mabel's face lit up. "Twin Powers!" she crowed, turning the sweater around. There it was, just as he remembered; sparkling, fake jewels spelling 'Alpha Twin' hot-glued into place. He'd seen all this before. He'd lived it. In two weeks' time, Bill would somehow destroy the barrier between the Mindscape and Reality, and Mabel would be…

Dipper's head swam with memories. All of the events of the previous two weeks flooded into his consciousness, as if remembering this one connection had unlocked a door in his mind. Images of everything he'd seen, said, and done came roaring into his conscious mind. The birthday, the presents, his fight with Mabel, her running into the woods, and-

He couldn't stand to think about it. Had had to act fast, and figure out what had happened. It dawned on him suddenly that it didn't make any sense. How could he be here if he had been hit with the same beam of energy Bill had used to…shouldn't he also have been…?

'Maybe Mabel was sent back as well?' he thought. Perhaps if he could make her remember something, he could get her up to speed. "Mabel, we need to talk." he said. "Do you remember anything…strange about yesterday? Any weird dreams that you had? Anything scary that happened?" Mabel gawked at him, puzzled. "Not really, bro-bro. The only dream I had last night was UH-MAY-ZIIIIING! Waddles and I were in a spaceship, flying through space! Captain Waddles!" She cried, looking positively delighted at the thought. Dipper scratched his head. "Are you sure nothing else sticks out?" he pressed. Mabel stared thoughtfully. "Nope!

Dipper sat on the bed. He knew his hunch was correct now. All he needed to do was make sure that he kept an eye out to stop Bill from breaking the seal. He turned to Mable, who was now looking through a box of old birthday decorations. "Mabel, I think something bad is going to happen."