Dipper saw the man dressed in black holding his bleeding sister, a chisel in his hand. He didn't need to know all the details, he just knew Mabel was in danger.
"Now you can get the blood close to your face." The man whispered. "And just to make sure you're silent..."
"NO!" Dipper shouted, the man in black turned his head back towards Dipper, who was standing up.
"What? You -" The man uttered in confusion. In a split second, Dipper grabbed a big lump of seed, blood, shit and vomit up off the ground and hurled it into the man's face. "ARUGH!" The shit/seed/puss/blood mixture burned like lemon juice in the man's eyes. He shoved Mabel down to the floor, dropping his chisel and stumbling back. Dipper stood up and ran towards the man, tackling him to the floor and choking him. Mabel sat up and saw the chisel on the ground. With lightning speed, she jolted up and grabbed it.
The man managed to regain his composure and easily overpowered Dipper, rolling over and pinning him to the ground. He growled and grunted as he wrapped his hands around Dipper's neck and began to choke him. Dipper hacked and wheezed, and the man was filled with blind anger, ready to end Dipper's life in a moment.
He never saw Mabel, never knew she had his bladed weapon. He never saw it coming she swung the chisel down and pierced it into the back of his head. "ARRRRGUGH!" he screamed, gurgling blood as it built up in his mouth from the back of his throat.
"How do you like the taste of your own blood, 'ya gross bastard?!" she gripped the handle of the chisel tightly and began to tug.
"No! No! Don't do it!" The man pleaded, knowing what was coming next. Mabel ribbed the chisel with all her might, and a chunk of brain and bone matter came out with it. The blood came spraying out of the back of his head like a broken soda fountain. He tried to let out a pained scream, but all that came out was a "screeeeeeech" sound from the back of his throat that grew quieter as it went on before halting completely. The man's eyes rolled into the back of his head, and he fell to the ground on his side. With the last of his remaining strength, Dipper pushed the man off him and collapsed onto himself.
Mabel ran to her brother and wrapped her arms around her brother's limp body. She was only a little girl, she didn't know how to check a pulse or recognize a heartbeat, or slow breathing. But now she could tell Dipper was alive. He was on death's door, but he was still alive.
"Dipper? Dipper! Are you alright, bro-bro? Say something!"
"Ugh, I'm pretty much the exact opposite of alright." Dipper replied. Mabel smiled and hugged him tightly. He was still lucid enough to make jokes, that was a good sign. But if she took too long, he knew her brother wouldn't be alive much longer.
She was bleeding from her stomach and face, but it wasn't too bad. She figured she suffered worse cuts playing with Waddles. She'd need to get medical attention along with her brother. Without a second thought, she tossed her brother over her shoulder, his pasty, naked ass like two inches from her face, and she ran towards the door.
Mabel tackled the bathroom door open, chisel in her left hand and Dipper and over right shoulder, and began to run out. She halted in her tracks when she saw five strange, hideous figures blocking her path. There were two men and one woman, they all had white, rotting skin and exposed viscera poking out in various holes all over their bodies like zombies. They had pure black eyes and their mouths had no lips, exposing their yellow, chipped teeth. With the exception of the one in the front wearing a black robe and holding a torch, they were all dressed like Taco Bell employees, including the one Dipper had seen earlier, his true form revealed.
"Halt, mortal!" One of the ugly beings shouted out.
"Ahh! Grody!" Mabel remarked. "Who are you guys? The Toxic Avenger's less successful siblings?"
"We are The Craven." One of the monsters hissed back at her. "For centuries with hid in these woods, luring mortals like you to their death. We've disguised our domain as typical human locales to lure them to their death. We place strange chemicals in our food to make them delirious, even the odor can alter your state of mind! Finally, when they're unconscious or dead, we eat their flesh and shit, bathe in their blood and seed, and drink their piss. We've disguised our lair as taverns, brothels, and in more modern times lowly fast food restaurants. You cannot escape! Submit to our will and die painlessly."
Mabel frantically looked around for an opening, but instead found something even better. The foolish zombie-men had installed a faulty gas pipe in the roof. Thinking quickly, Mabel tossed the chisel at the gas pipe and it split open, shooting a powerful stream of gas down on the zombie-men.
"Argh! What trickery is this?!" the cloaked leader shouted as he shielded his eyes, dropping his torch to the ground. The torch ignited a great fire, engulfing all five of the zombie-men, who screamed and dropped to the ground. Mabel jumped over their burning corpses and rushed towards the exit, never looking back as the fire spread and soon engulfed the entire building.
Mabel loaded Dipper's limp but conscious body into the Mystery Shack go-kart she rode to the store. She slammed her foot on the gas and the twins escaped. The burning Taco Bell behind them and the heat crawling down their necks, they both felt a sense of relief as Mabel sped away as fast as the kart could go.
Dipper was slipping out of consciousness now, unable to stay awake as his vision grew blurry. He weakly moved his hand towards his sister, and she held his hand in her's. They both looked at each other, and a sense of calm came over them. As he fell unconscious, the last thing he saw was Mabel pull into Gravity Falls, finally free from the dark forest.