Wow I finished this one really quickly. Yay! (Don't expect me to be so on top of things in the future. I'm not a fast writer. Sorry !)

Just to be clear, after the divorce, Mabel went with their dad and Dipper went with their mom.

In the shadows of the towering pines, creatures scurried in and out of their hidden haunts, too busy living to be bothered with the insistent message carried on the wind. It danced through the undergrowth, stirring up discarded pine needles and forgotten memories. Most creatures may not have been bothered by it, but one in particular took special care to make sure he heard all of what the forest spoke of. He listened patiently to the voices carried by the wind and watched as it twirled away to speak to others who didn't care. But he did. Most of the forest, or even the town, might not know it yet, but this was going to change everything.

Things were about to become very interesting.

...

"You still haven't explained the pig."

He leaned to his left at an alarming angle as the car he and his twin currently resided in raced around a bend in the road. The magnificent pines around them filtered the falling rays of the setting sun and sent shadows dancing across every surface they could reach. It was quite beautiful, but Dipper was distracted from it all by the loud, enthusiastic entity that was his sister.

Mabel was without a doubt one of the most social people he had ever encountered. She hadn't stopped talking ever since she had nearly killed him again (Seriously, this girl was going to be the death of him, and it wouldn't even be a cool way to die. 'Strangled with love by his sister' was not something he wanted on his headstone.), and he had been introduced to an obviously shady older man with an eyepatch who was apparently their Grunkle Stan. Topics ranged from art to television shows to life goals to candy preferences, and her enthusiasm for anything and everything was contagious. Even if he really didn't care about what was the most appropriate color of glitter to have on your face in different situations, he found himself arguing playfully with her over the merits of blue over purple.

It was comforting to just talk to someone like this. He was so hopeless in social situations that most kids back home had given up even trying to speak to him. He would never admit it, but it was a very lonely existence. The phrase "I'm fine" had, as for so many others, been repeated so often that it had become a mantra he could no longer believe.

As he listened to Mabel's rambunctious laughter and took in her radiant smile, he felt as if he could finally belong somewhere, instead of being lost in a confusing world where no one understood him.

Mabel scooped up the pink creature and squeezed it affectionately to her chest, ignoring its desperate attempts to win back its freedom. "This is Waddles! I'd been trying to convince Dad to let me get a pet for ages, but apparently lions 'aren't the best thing for suburban living.'"

Dipper patted her arm consolingly. "So Waddles was the middle ground?"

"Yep!"

Waddles seemed to grow tired of all the affection he was receiving and leapt into the passenger seat. Grunkle Stan let out a surprised yell, and the car swerved dangerously, tires screeching in a banshee-like howl, before settling (thankfully) into the correct lane. Dipper sank into his seat in an attempt to avoid the glare directed at them from the rearview mirror. Even if it wasn't only meant for him, he had the strange urge to hide as the single uncovered eye met his gaze for a moment before returning to scan the road ahead. Mabel, seemingly oblivious to their Grunkle's anger, continued chatting about whatever was on her mind. Fishing around for some sort of distraction from the unhappy gaze, he remembered a question he had been meaning to ask earlier.

"How did you know to call me Dipper?"

He could practically feel Mabel's confusion. It fused with the annoyed atmosphere created by Grunkle Stan, resulting in a completely awkward situation for him. God, he should have left it alone. "Isn't... that your name? That's what Dad said it was."

He was such an awful person. Why had he asked her that? Mabel looked so unsure of herself, which didn't suit her after seeing her so confident before. He laughed uncomfortably and tried to wave away the problem he had unfortunately created. "Oh, yeah, but it's a nickname. I didn't think you'd know it."

"Oh, okay!" And just like that, Mabel was back to her chipper self. Dipper breathed a small sigh of relief before grinning back at her. He hadn't screwed this up yet. "It's a really cool name! But, um, why Dipper?"

"Because..." She wouldn't make fun of him, would she? She didn't seem like the type, but he had been wrong about that before. He looked away from Mabel's curious gaze and chewed his bottom lip as he thought. Should he show her or make something up? After agonizing over it for a few seconds, he finally gave in and pushed his bangs off of his face, keeping his gaze firmly set on the faded grey interior of the car. He would use this as a test to see if she was really as nice as she seemed to be.

Mabel gently traced the birthmark that spread across his forehead: a mess of dots and lines that came together to form the shape of one of the most famous constellations in the sky. She slowly came to a halt when she reached the end, causing Dipper to look up to gauge her reaction. He was expecting her to laugh, mock, or ridicule him. Instead, her finger slid down from his forehead to his nose, which she then tapped lightly before pulling back. "Boop!"

Laughter leapt from his mouth before he could smother his surprise, ringing loudly in the confined space of the car. Mabel giggled along with him, and Waddles contributed a snort or two to the cacophony. Dipper reveled in the noise, trying to remember the last time he had been so relieved. Mabel liked his strange birthmark, and she seemed to like him, too. Maybe, they were both just strange enough on their own to make things work together.

As they laughed, they both failed to notice the interest they drew from several different sources. The intense stare from the rearview mirror slipped away as Dipper looked up, but one remained. It followed the car as it sped on to its destination without wavering, a constant presence that left an odd tingling sensation on the back of Dipper's neck. It was watching, and waiting for the perfect moment to strike. Watching as the sun sank lower on the horizon and was swallowed up by the land. Watching as the sky filled with smaller pinpricks of light that humans had spent ages weaving tales of, watching as a certain grouping of these lights seemed to gleam brighter than the others around it. Watching as the town of Gravity Falls slowed to a halt, blissfully unaware of the events that were about to transpire.

Always watching.