Dipper Pines heard laughter. It felt like it was echoing through him, like layers of himself were getting pulled off by it and then being reassembled into something alien. Beneath the laughter, Grunkle Stan was yelling and he sounded...scared. Why did he sound scared? Mabel screamed and her hand was being ripped out of his own, over and over again in his head.
(He should have held on. Why hadn't he been strong enough?)
Symbols played across his mind, symbols and pictures of places he'd never been. Some were empty and dead and inhabited only by the shapes of things that once were.
The symbols changed. They changed from what they had been in the book, no more hand, no more hungry fish, no more shooting star. There were new symbols now and they were suddenly seared painfully in the back of Dipper's mind, flashing bright in the black behind his eyes.
Red square. Pink diamond. Gold circle. Green upside-down triangle. Orange octagon. Blue hexagon.
Only the green triangle and the blue hexagon were free. The others were wrapped in shadow, wilting, plants choked by weeds.
...And the black hexagon was the one at fault, a coffin that opened him up and swallowed him whole. A hole in the heart of the shadow-corpse in it led into the void where the nothing devoured everything.
The pyramid watched it all with its ever-seeing eye.
Dipper heard his laughter and hated it. It was deafening as the door opened and shut behind them, and somehow he knew deep in his heart that he was now in another
place that had a door in it that shouldn't have been opened.
"It's just the start. Haha!" Bill Cipher laughed and then his voice became deep and terrible. EXISTENCE IS AN ILLUSION THE DOORS ARE OPENING THE LAST FORSAKEN DOOR WILL BRING THE LONGEST NIGHT AND THE CHILDREN WILL WEEP AS THE WORLD ENDS
Dipper sat up with a start, holding a hand to his chest and gasping and found himself in a dark woods. It was night, and the only light came from the full moon, filtering down through the leaves. The air was cool and still and buzzed with the strange creaking chirps of cicadas.
This was not Gravity Falls - the trees all looked wrong. There were pine trees, but not enough.
Dipper couldn't remember how he'd gotten here through. The last clear memory he had was of him and Mabel goofing around in the Mystery Shack but he was having strange flashes of something after, something...big. Something big had happened but there was an empty space in his head where the memory of it should have been.
"Mabel?" he called out, quickly climbing to his feet, feeling the panic well up as he realized she wasn't right near him. "Mabel?!"