A/N: If I could add two more genres, it would be angst and horror, just to let you know. This story is also on AO3 on its 7th chapter, but I just got the idea to cross-post it here, wow. I'm jerseydevious on both tumblr and AO3 if you have any questions!

Before I start, I want to warn you that this thing starts out bloody and gets bloodier. I have no mercy. I am not a kind author, and these kids are going to struggle. In this prologue, there's trigger warnings for temporary character death and graphic depictions of violence - and, of course, Bill Cipher being Bill Cipher.

It smells like blood and oak trees. Dipper shivers.

Gravity Falls is slaving through the thick of the dog days of summer; the heat is blazing and miserable. It feels something like evaporated blood, if evaporated blood was a thing, and if it is, Dipper doesn't want know and he doesn't want to think about that.

Because, right there, is an ocean of his sister's blood, soupy and congealing and gross. It's a sick, dark red, almost purple.

There's no wiping his memory of that. That image will stay with him through thick and thin and rain and shine, it will always be there, he's sure of it. He's enslaved to it. Her blood is thick on his hands, and he feels like the monster in the corner of the room that no one sees and no one notices and he feels like the worst of them all.

This all hypothetical, of course. These are fake little thoughts that he'll never think again, products of the heat and intensity and the crippling fear. In real time, his sister is bleeding out before him.

Ha. What a joke. She's already bled out. She's blue. She's been here for a while.

He should have gotten here sooner. He should've - he should've done so much more than what he did, he should have - he should've -

Dipper's on the ground, now, pride thrown out somewhere behind him, face-first in the blood soaked dirt. Sometimes, he hates being the logical one, like now, because he knows - logically - that there's nothing he can do. He's too late. He wasn't fast enough, wasn't good enough. He knows, logically, that it's all his fault.

He can't even tell himself that he'll do better next time, since there won't even be a next time. He's alone. She's - taking an extended vacation, forever.

For a blinding moment, all he wants to do is go with her. He's never been a hopeful person. But, today, for right now, he'll hope against all hope until there's nothing but hope left; that sounds nice, a life of nothing but grasping at straws. At least there's something to hold on to.

Nice isn't good enough. Only Mabel is. He needs more than hope. He needs - he needs -

"You flatter me," Bill said.

Dipper is filled with a sudden, inexplicable rage - but he quells it. He's got cards to play. He's got something Bill wants, or he wouldn't have showed up.

"Right on that count, P.T.," Bill said. Dipper doesn't let his surprise show, even if the demon knows it was there. It's better than being exposed, like a field without grass and trees and just the great big sky.

"A deal," Dipper said. He's pleasantly surprised when his voice comes out stronger than he thought possible.

Bill blinks at him - or, depending on the intent, winks at him. It's hard to tell. The demon twirls his cane. "Name your terms, Pine Tree. Gotta say, I like this change of heart!"

Dipper pushes himself out of the dirt. And, yeah, maybe that part hurt his pride just a little, but it could withstand the blow. "You heal Mabel's wound - the physical, fatal one, and you replace the blood she's lost with her blood type. Not all of it, just enough so that she's alive and can survive the loss. You take the blood she needs from me and no one else."

Bill cackled. "What a nice thought, Pine Tree, but I need a life to ruin here! I'm not a demon for kicks, y'know. Or, maybe I am, but that's a universal secret."

"Ruin mine," Dipper said. "Take whatever - whatever you want from me. But it's got to come from me. Blood or bones or possessions. My friends and family don't count."

Bill's singular eye gleamed. "Whatever I want? My, my, Pine Tree - that's a steal! I honestly can't let you walk away with a deal like that, and I'm me!"

Dipper swallowed against the look in Bill's eye. It was beyond predatory - it had crossed into psychopathic eighty miles back. "Yes, you can."

Bill batted his eyelashes. "You know me too well! What a partnership we've got - I'm winning left and right!"

"Heal any other wounds that might threaten Mabel's life," Dipper said.

He pauses, for a hair's breadth of a second; he can't outsmart Bill. He could sit here all day and spew out rules for a contract and Bill could still manipulate it to his gain - could, and would. If he can't outwit a silver tongue...

"She… she can't die until after I do," he finished, in a rush. Dipper gripped Bill's cold, black fingers. "Deal."

Then he'll just have to out-speak him.

Dipper, after a little reading, had discovered that demonic deals are sealed as soon as physical contact occurs between the negotiators; by jumpstarting the deal, he deprived Bill of the chance to analyze the points Dipper had added. It was as close to a hidden fee as one could get with a verbal contract.

Dipper's heart seizes. He can't take it back, and there's no telling what could happen; Bill could just kill him and then kill Mabel right afterward. Bill could - he could - there's no telling what he could do, and there's absolutely no way for Dipper to stop it.

"Deal," Bill said, his eye turning blue. "Wait - what?"

Dipper let go, reeling with the cold, icy - but blistering - sensation of the azure fire crawling up his arm. He held his right hand gingerly. "You heard me."

If Bill had a mouth, he would've gaped. "What a dog, Pine Tree! Guess I'm teaching you something after all. I protect your sister for as long as you live, I get whatever I want to take from you, whenever - it's still a bargain."

Dipper swallowed. Right. I should've specified that he could only take one thing from me, Dipper thought. One more thing I failed at. And I should've told him to take it immediately.

Dipper feels a weight settle on his shoulders, heavy and spiked with pure, banal fear, the kind that causes wolves to attack things larger than they are. It's horrible. He'll live with it until Bill collects, and, suddenly, Dipper gets it; this is what Bill wanted. He wants to drive Dipper crazy. It's the first thing he'll take.

Dipper shudders.

Bill's eye narrows, like he was smiling under his bow tie. He tips his hat. "Just a tip, Pine Tree - eyes to the sky! You never know when it might do something crazy, like change colors! And, of course, the sun could always explode. Gotta love those celestial intentions. Oh, and save the teeth for me."

The gray leaches out and flows into Bill's being, taking away the dull horror of the Dreamscape and replacing it with the brilliance of Oregon's forests. "To the end, Pine Tree."

A/N: What do you guys think? Questions, comments, concerns - leave 'em below or at .com! Remember, I'm always hella thirsty for encouragement. I feed off of tears. It's been proven. My tip to you - remember every single detail you see, because it will come back up later. (BTW, the real chapters are usually upwards of 10 pages, so expect MASSIVE updates compared to this.)