Yep, looks like it's another weird AU from moi.~ This time, I'm trying my hand at Gravity Falls. I actually started writing this story a while ago, thought about ditching it, but came back with renewed interest after watching the GF finale. Anyway, long story short, I'm now posting this on the Internet to see what people think and offer their opinions on whether I should continue or not. This goes without saying but any feedback, be it good or bad, is greatly appreciated.~

Anyway, a few things to say about this story before you start reading. It should be obvious from the character settings but this is a BillDip fanfiction, the central pairing will be BillDip, so if you don't like it, you'll be wasting your time reading it. There will also probably be side pairings, the details of which I'm not quite clear on at this point, but there is a high chance of Mabcifica occurring. Just wanted to make that clear.

The rating is set at T for now because I have never been willing to write smut. However, there will be angst. Lots and lots of angst. Did I mention that this was a BillDip fanfiction? Yeah. Angst.

Virtually all the non-adult characters are aged up in this AU, with possible exceptions. They're university student age, so somewhere between 19 and 25. Stan and Ford are about ten years younger for the express reason that they remain alive. Bill takes on a human form (I have nothing against triangles, believe me, that's honestly just the way I prefer to write him). As for everything else... I'll leave you to find out.

I very much hope you enjoy.

-Le Fez-Wearing Husky

Prologue: Beyond Extreme

He could see nothing.

Well, technically, that was a lie.

There was in fact a generous amount of light. It radiated from multiple sources, casting distorted shards of illumination over the khaki walls of a sizeable tent.

An upended torch serving as a makeshift bedside lamp shot light directly upward, illuminating the numerous pinups tacked to the tent's folds; high-resolution photographs of hieroglyph-carved relics incessantly drawn over and annotated; crisp sheets of paper almost obscured by scribbled ciphers, symbols and algebraic equations.

A circle of eight vaguely antique candles, their wicks glowing an unnatural blue shade, surrounded a sleeping bag hunched in the centre of the tent. A very faint, almost unnoticeable, breeze blew inward from the Saharan crepuscule through the numerous rips in the tent's fabric, causing the flames to flicker, so very slightly.

The human contained within the sleeping bag hunched over himself, shivering. Brown eyes scanned the not-darkness relentlessly. Nothing. He was alone.

He waited for so long, in such utter desperation, he almost began to weep. But he caught himself before he could. There was no way, no way in hell or whatever diabolic dimension existed out there that he would ever let himself do that in front of… of him.

His shiver intensified when he realised that was probably exactly the reason why he hadn't turned up yet. Just piling on the psychological torture. Teasing his sanity out from within him like a thread, little by little, reducing him into the madness that he had always had the potential to become.

"You… you're still there, right?" He fought to keep the emotion out of his voice. "We still have our deal, right? Right!?" An octave of pure fervent desperation vibrated off his tongue, rattling through the air as though through a skeletal body.

"Sssh," a soft voice, emanating from seemingly nowhere, sounded. The brown-haired cryptologist almost jumped in response to a light pressure against his lips. Two fingers, gloved. The digits glimmered with ethereal, oneiric radiation. A pulsating pulsar, an electromagnetic anomaly. Bowtie, cane, top hat and tailcoat; your typical steampunk aristocrat with a passion for the colours yellow and black. Save for the one visible eye, the catlike iris that gazed upon him, full of something that the cryptologist could barely describe or understand. "No need to shout, Pine Tree. I'm right here."

The demon hung upside down in a casual, mocking fashion. He flicked the tip of the cryptologist's nose with one hand whilst simultaneously twisting a finger of his opposite hand through a lock of the former's hair, as though he owned it. The brunette squirmed at the contact, but did not attempt to break free.

"You… you did this on purpose… didn't you?" The young cryptologist considered that he should probably be exhibiting feelings of anger towards the demon, but instead his speech was resigned. He was unable to contradict the waves of relief that drowned out almost all other emotion.

"Well, it just so happens that the sight of you scurrying around, getting your little head all anxious and worried, being unable to think about anything but me… well, it's all highly amusing." A sudden pixelated, glitchy distortion, and the demon was the right side up, floating mere centimetres above the cryptologist's body. "And not to mention flattering."

"...That… that's not true!" the brunette hurriedly denied. He could feel his cheeks burning with a painfully familiar sensation as garbled chains of profanity shot through his mind. "I'm not that obsessed with you. I just… I just want answers."

"Say that if it makes you feel better, Pine Tree." The demon shrugged. "But I know. I know you better than you ever could. Y'know?" He chortled. "No, of course you don't. You've come a long way since we first met, sure. But you still don't know shit. I mean, you really don't know anything."

"I know that," the cryptologist muttered defensively. "That's why I tried to summon you again. I've been waiting for nights. There's one thing missing from this equation. Something only you could find. I need you."

"So, I've finally made you willing to beg. What does this mean for me? Do I get what I was promised?" An unfathomably golden iris bored into the brunette expectantly. An intent smile settled on his features. "So, Pine Tree? What's it going to be?"

The cryptologist gulped. But before he could respond, the demon's hand moved.

Caressing his cheek, stroking his neck, trailing ever so subtly down his exposed chest. That oneiric touch left a subconscious mark, a sensation from a dream, experienced during wakefulness. The sensation caused the cryptologist's body to shudder from head to toe. "Ah…" He could barely handle it. This… teasing. It was, quite literally, driving him insane.

"What's it going to be, Pine Tree?" the rhythmic question came again. The brunette barely noticed it; he was far too fixated on the demonic contact that was giving him that so oddly pleasurable sensation. A sensation made almost physical by the demon's burgeoning power.

All too soon those gloved fingers had moved back to his cheeks, cupping them, squeezing them forcefully, as though the demon was attempting to mould frozen plasticine. "I'm sure this will help you make up your mind."

Before the cryptologist could register movement, ethereal lips connected to his own. Intense, indescribable feelings. No words truly existed to convey that particular experience. The cryptologist felt some part of the demon enter his body, but it was not conventional; instead, metaphysical. A glimpse of knowledge beyond the limits of perceptual understanding. A tiny window into an infinite world of omniscience. Of information so primordial that it transcended time itself, eternally. Of the world that the demon inhabited. Even that miniscule insight was almost too much. A sharp, unphysical pain bolted right through the brunette, leaving a meta-throbbing in its wake. He gasped as the vision left his mind, almost as quickly as it had entered.

Gloved hands travelled back to his neck and waited, waited for the vibration of his larynx that would signal his answer. The cryptologist was enthralled. Defeated.

"…Do it."

"Gladly."

Memories rushed together, faster and faster, until they reached the point of convergence. The cryptologist was ripped from the body he had once inhabited independently and then merged back into it, now part of a bigger whole. Psychological chains immediately bound him, tethering him, constraining him. The agony exceeded any known limit. He gasped, and his lungs filled with the air of his own dreams.

How did it come to this?