Disclamer: Regrettably, I don't own Gravity Falls, it's characters, the quote in the summary, or the Stanley Twin Theory. Untegrettably, I do own my ideas and my take on the theory in question.

Dipper Pines paced around and around a dusty, cobweb-ridden room, pondering on whether or not he should open a box.

Yes, this may sound silly, but Dipper took problems very seriously.

He wanted to start opening the boxes, but his sister and friend weren't here yet.

Beginning to lose patience, Dipper stopped pacing and checked his watch. I told them to be here at precisely 7:43 PM! It's just now 7:47! Where ARE they?! He thought. He began to pace again.

Dipper, his sister Mabel, and his friend Soos had all agreed to clean out Soos' new break room At exactly 7:43. They weren't going to throw anything out, just in case something was worth a lot of money or if it had sentimental value to their great uncle Stan. It had seemed the perfect day to do this; it had rained hard all that day and no tourists had showed up at the Mystery Shack.

It was Mabel who had suggested they help Soos, and Dipper, who was decoding a cypher in his journal, had refused at first. He had seen Stan's look when they had entered that room for the first time. He didn't think Stan would approve if they started going through all that stuff. But Mabel finally convinced him that it was "for the greater good", and Dipper reluctantly agreed. Dipper had ran into the room as fast as he could, and would let Soos and Mabel in once the coast was clear. Mabel and Soos were on guard duty (both of them laughed for a long time when Dipper said the word "duty"); they had to make sure Stan was nowhere to be found so they could go into Soos' break room without having to answer interrogational questions.

If they were dealing with Stan, it wouldn't hurt to just open one box...would it?

His curiosity getting the better of him, Dipper scrambled to the back of the room and pulled out a large cardboard box, the one that was farthest back. He pulled a Swiss Army Knife out of his pocket and cut the packing tape, then gently opened the flaps.

The box contained photographs.

Lots of them.

Dipper sucked in his breath and started going through the Polaroids. There were stacks of various pictures, most of them near the top of the box were of two, but occasionally three men who all looked like they were in their late twenties or early thirties. Dipper picked one up and stared at it.

Three men were pictured sitting around a round table-the exact one that Stan kept near the living room of the Mystery Shack. Two of the men were poring over a stack of papers, the third was sitting across from them and laughing, feet on the table and a cigarette in his right hand. The man's face was somewhat familiar - Dipper was sure he had seen it before. The man had deep brown eyes, oak brown hair that was slicked back into what appeared to be an untidy scruff, and had slight stubble and a square jaw. He wore dark jeans and a tight-fitting white tee shirt that showed muscular arms and a six-pack. Glancing at the man's face, Dipper noticed that his expression locked both amused and cocky- like he was playfully teasing the other men. With a gasp Dipper suddenly realized who the man was: It had to be a younger Grunkle Stan. Dipper hurriedly looked at the other people in the photograph.

The other two men were sitting next to each other and poring over a stack of papers that contained nothing but jumbled letters. The man on the right appeared to have been speaking when the picture was taken, as his mouth was open and his hand was in the air. He was the same height as the younger Stan, and had similar features. His eyes and hair were brown as well, but this man wore black Wayfer glasses and his hair was much untidier. He wore a black shirt underneath what appeared to be a lab coat, and a chewed-up pen was behind his ear. He looked like a scientist of some sort.

The third man was much shorter than the others, but Dipper assumed that he was several years older. His hair was a lighter brown -almost ginger- and very untidy, as if he frequently ran his hands through his hair. Small glasses were perched upon a long nose, and this man's eyes had dark circles underneath them. He was hurriedly scribbling notes on the papers, and had a look that was half exhaustion and half annoyance. He probably was trying his hardest to endure Stan's teasing. Dipper was positive he knew who this man was: he had seen that face in a memory about a week ago. It was a younger Old Man McGucket. So was he called Young Man McGucket back then...? Dipper gave a small internal smile and flipped the photograph over.

Someone -probably a woman, judging by the handwriting- had written the words

Stanford, Stanley, and Fiddleford: February 1982

1982... That's the year of that calandar on the wall by the door. What had happened in 1982 that caused this room to be boarded up and forgotten? Dipper thought. He clutched the photo, staring at it intently.

His mind brimming with questions, Dipper dug down deeper into the box and pulled out another photo. This one was close to the bottom if the box, and was even older than the last picture. It showed two young boys, nearly identical, sitting at a table in a place Dipper didn't know. One boy was holding a thick book, and the other was holding up a diamond ring and smiling mischievously. Thr first boy was smiling and rolling his eyes. Dipper assumed the one with the ring was Grunkle Stan, and the other boy "Stanley". He flipped the photo over.

Stan Twins, age 8

Dipper sat up hurriedly, gripping the two photographs. He had photographic EVIDENCE that Stan was hiding a twin brother. He had to know more. Dipper began to move towards the other boxes, but a loud bang and his sister calling his name brought hm away from his investigation. He scurried out of the room, heading towards his sister's voice.

-Thirty Years Lost, Thirty Years Forgotten-

Mabel and Soos had searched every single nook and cranny in the Mystery Shack, and they could not find Grunkle Stan anywhere. They searched his office, his room (Soos took pictures on his phone), the living room, the gift shop, and they had even searched outside. Stan's car was still there, which meant that he was either in the house or had walked somewhere. The latter seemed unlikely, so Mabel peeped in the windows of the old El Diablo and looked inside, wiping her hand across the window so rain wouldn't get in the way.

"Grunkle Stan's not in here either, Soos," Mabel remarked as she faced her friend, "where could he be? The Bottomless Pit?"

Soos shook his head. "Naw, dude. No time would have passed or whatever fourth-dimension stuff went on in that pit. Mr. Pines probably isn't in there."

Mabel comically put a hand to her chin. "Where could he be...?" Her eyes wandered around the lawn and surrounding forest, looking for potentional hiding places. He glanced at the front of the car, and a thought struck her.

"Hey, isn't Grunkle Stan's real name Stanford?" Soos nodded. "Then why does Stan's license plate say STNLYMBL? Wouldn't that mean Stanley Mobile?"

Soos looked uncomfortable. "I dunno, dude. He probably changed it so the fuzz would've catch him."

Mabel thought about this as she entered the Mystery Shack and shook her hair to try and dry it. Waddles trotted over to Soos and sniffed his foot, then sniffed the air. He wandered over to the vending machine and tried to lick the side of it.

Soos tried to gently push the pig out of the way. "Uh uh, dude. I don't think Mr. Pines would like that."

Mabel scoffed, smiling. "Whatever, Soos. Grunkle Stan loves Waddles; I'm eleventeen percent sure that he wouldn't mind. Now Waddles, what kinda snack do you want? There's log candy, gummy koalas, ooh, there's some Pent-A-Grahms! I want one of them all!" Mabel pulled a five dollar bill out of her sweater pocket and started pushing buttons on the vending machine in a familiar order.

The handyman sweatdropped. "Uh, Hambone..."

The vending machine swung open violently and hit the wall with a loud bang. Mabel peered into the entranceway now unblocked by the vending machine, and saw what looked like an elevator. Mabel was super excited. She finally found something cool and mysterious before her brother did! "DIPPER!" She called ecstatically. "COME CHECK THIS OUT!"

In the blink of Bill Cipher's eye, Dipper bolted into the gift shop. He looked a little worried, and was tightly clutching two small pieces of paper. "Look! A secret entranceway-thingy!"

Dipper looked impatient, but intrigued. "Let's go, then we can find Grunkle Stan. There's something I need to ask him." He explained what he called "The Stanley Twin Theory" to Mabel and Soos, who Dipper noticed looked a little anxious. "You okay, man?"

"I dunno, dudes. This place gives me major creepo vibes...that weird elevator isn't helping."

"Creepo, shmeepo." Mabel smirked amusingly and stepped into the elevator, pressing the button for the third floor. "Besides," she added somewhat comfortingly to Soos when the elevator began its descent, "it's not like we'll get caught."

Mabel had barely finished her sentence when the elevator stopped and the doors opened to a furious Grunkle Stan.

"Dammit, Mabel..." Dipper muttered as their great uncle grabbed both of the Twins' ears and led them to a small room

-Not Quite Forgotten-

Dipper had forgotten how scary their Grunkle Stan was when he was angry.

At first, it seemed like Stan was going to explode, now he just looked like a fuse that had just been lit. Dangerous.

"What." He growled, barely opening his mouth, "The hell. Are you. Doing here?"

Mabel blushed and looked at the floor, and felt somewhat inclined to do the same. But anger overtook his fear and he pulled the two photographs out of his back pocket.

"How many secrets have you been keeping from us?! First the wax room, then the body-switching carpet room, now this?! I can't believe you!"

Stan glared at him. "The only reason I kept this from you and your sister is that you wouldn't get hurt!" He pointed a finger at a window in the room, where a bright blue light shone in the shape of a triangle and surrounding circles. Dipper felt like he had seen something like that before, but couldn't put his finger on it. "If you knew about this, you would be incredibly stubborn and try to test this out yourself! I know how stubborn you are, ok?! I didn't want anything to happen to you!"

Stan glared at Soos. "How come you told them?" He whispered in a dangerous voice. Soos gave a sort of whimper and shrunk behind Mabel, who defensively put up her arms. "Hey, it want his fault! You're the one who's keeping secrets from us! I thought we could trust you!"

Angrily, Dipper pulled out the photos. "That's not all your hiding. Who is this guy? Is he really your brother? HOW COME YOU BEVER TOLD US?"

Stan stopped, and stared at the pictures. He made a movement as if to reach out and touch then, but decided against it. "Where did you get those?" He asked in a softer tone than before.

The boy glared. "Answer my questions first. Who was this guy?"

Mabel Put her hands on her hips. "I want the whole story. NOW!"

Stan gave a step back in suprise and sat down on a spinny chair. He sighed, and put his head in his hands. To Dipper and Mabel's suprise, their great uncle's shoulders began to shake. Was he...crying?

When Stanford finally lifted his head, he wiped his eyes with the back of his hand. He looked at the twins, and silently noted that Soos had gone. It didn't matter. Soos was probably eating something upstairs anyway.

"Fine. I'll tell you as long as you two promise never to tel a soul. Agreed?"

They both solemnly shook their heads.

"All right." Stan gave a deep breath. "It started like this..."