"Man, that heist was golden!" Stan beamed as the battered remains of the golf cart chugged back into the Shack's car park in the dead of night, nursing his black eye and swollen jaw. "Sure hope somebody catalogued that one for posterity!"

"Frankly," Ford said, stitching the scar on his left bicep, "I'd hope it goes forgotten. That was far more violent than I was banking on, Stanley."

"I punched that guard so hard I think my knuckles are permanently purple!" Kevin cackled, holding his sore hand. "He must have been 300lbs!"

"Not as hardcore as Dipper kicking the window through!" Pacifica beamed, wrapping a bandage around her boyfriend's knee and simpering over his bravery. "That was - that was wow!"

Dipper grinned awkwardly, trying to ignore the crippling anxiety that his knee might have half of a glass pane stuck in it. "I'm capable of being actiony too, y'know?"

"Especially considering we didn't even need you to break the window!" Kevin beamed, throwing his arm around Dipper's neck. "You're a total maniac!"

"Heh, heh - yeah. Just- do - don't go on about it, huh?"

"That," Mabel chirped, picking a security guard's tooth out of her sweater, "Was totally the highlight of the entire Summer! If people didn't see that, they were totally missing out!"

Stanley grinned as he swerved into the Shack's car park. "Shame I couldn't get that jewellery out of the case."

"Stanley, this was strictly a trip for what we needed." Ford snapped. "We'll take these things back tomorrow evening."

"Sure, just like the mushroom samples in your pocket. The boy scout gag's gettin' old, Sixer."

Ford chuckled and punched his brother playfully in the arm. "When you start researching the chemical properties of gold, you're free to take it. Deal?"

Together, the family dragged back the sack of antique miner's lamps, tools, and some lengths of minecart rail. It was everything you needed to convince a potentially sentient element that it was home. As cynical as Ford was as to the paranormal abilities of the coal sample, he couldn't deny that he was eager to see if there was anything of note.

Waddles watched curiously as the group piled through the door with their antique contraband.

"C'mon Waddles, we'll dress you up like a pit pony!" Mabel cheered.

"Sweetie, that pig ain't gonna pass as a pit pony. He'd barely pass as a pit pig."

Mabel's eyes widened. "Grunkle Stan, you're a genius! If I put a helmet on him, then he can be a chubby little miner man!"

Ford winced. "Mabel, sweetie, this is really important. You can dress him up, but maybe take him out of the room before the experiment?"

"Fiiiine, I guess." She huffed.

Waddles, completely oblivious, was too busy attempting to eat a pick-axe handle to bother listening to the quandary. Why worry when there's so many new flavours in the world? Of course, he was pretty willing to tag along with any of the plans Mabel put forward. He barely even noticed when the helmet was shoved onto his porcine bonce.

He simply sat down and watched, head slightly cocked, as the family got on with assembling their interior diorama - something the group did with surprising levels of professionalism. Mabel, naturally, installed herself as the art director.

"Left! No, no, my left!" She said, using a rolled-up magazine as a megaphone.

"We have the same left, Mabel!" Dipper replied, sharply.

"Do those look like two-foot-gauge minecart tracks to you, Dipper?! This has gotta be perfect! Those have gotta be two-and-a-half feet!"

He dropped the tiny rails in frustration and began to raise his voice. "We're in the middle of a boiler room -"

"Perfect! That's perfect, Dipper!" Mabel interrupted, clapping her hands. "Ideal! Perfectamundo!"

Pacifica tried her best not to snort-laugh as she tiptoed over the 'perfectly placed' rails and assembled one of many intricate rock piles. "You're a true artiste, hon."

Ford went around the room, lighting the fragile old lamps, while Stan tried to remove his barrels of definitely-not-moonshine. It was a perfect picture of collaboration. (Fitting really, as those barrels, according to Stanley, could make a perfect pitcher too.)

Within time, the stage was finished. The crew took a can of Pitt and wiped their brows as they admired their attempt at a film set. The boiler room basically looked like a big, rocky mess. Which was kind of what they were going for. Dipper ran upstairs to grab the sample bag. Then promptly ran out of breath and decided it was best to just walk.

Meanwhile, Mabel was inspecting her handiwork.

"I think it needs glitter." She said, tapping her lip.

Pacifica nodded sagely. However, before she could run upstairs to raid her craft collection, Grunkle Ford grabbed Mabel's collar and shook his head. "Not this time, Pumpkin."

"Aw man! Old times were boring."

"A worthy sacrifice." Stanford smiled. "I promise."

"If not, you owe me ten bucks!"

"Wait, what?"

Stanley laughed and slapped his brother's back. "The kid's learnt from the best, Sixer!"

Mabel beamed innocently and twisted her foot on the floor. Ford was just about to say something when-

THUMP
"This-"
THUMP
"Stuff-"
THUMP
"Weighs-"
THUMP
"A ton!"
THUMP

Dipper grunted as he dragged the hefty bag of coal down the creaking wooden stairs, with no small amount of difficulty. Finally, he forced it onto the sample table and dusted his hands, giving his brow a wipe and - in the process - covering it in soot.

"One bag of coal reporting for duty." He said, somewhat breathlessly.

"My strongman." Pacifica smirked, holding his chin.

Ford ruffled Dipper's hair and began arranging the samples, preparing a desk magnifier to observe any strange behaviour.

Stan rubbed his unshaven chin as he glanced around the room. "Y'know, this'd be a pretty decent tourist attraction. Could make it uh - y'know, one a'them escape rooms. Just lock the door and add a spooky ghost thing and-"

"Shh! Shh!" Ford hissed, holding up his hand.

"Did you just shh me?" Stan barked back, irritably. He soon fell silent.

There, on the table, the lumps of coal began to move unaided. They rattled away, bumping against eachother, tapping test tubes and bunsen burners as they vibrated frantically, growing increasingly violent and erratic.

The room began to shake. Piles of rocks collapsed, the miner's lamps swung back and forth on their wire mountings. The boiler rattled and rumbled, its gauge-needles vibrating back and forth. Pipes rumbled and clattered. Test tubes clinked. The table moved a couple of inches on its feet. Mabel dramatically pretended to fall back into Kevin's arms.

"Something's happening!" Ford said. "Absolutely nothing must change in this room!"

As if prompted, Waddles - who had been busy chewing postcards in the gift shop - trotted down the stairs and sat down, resplendent in his miner helmet. The family froze as, almost immediately, the coal simmered down and stood perfectly still.

"Why didn't you close the door?!" Ford barked. "For pity's sake, the experiment will be-"

CRACK-
CR-A-ACK
CRUNCH!

Coal dust flooded outwards.

Test tubes shattered.

Lamps burst into miniature fireballs.

The smell of kerosene filled the room as - within a split second - it plunged into darkness. A pitch black, tarry atmosphere that felt chemical and unfamiliar.

Pacifica clung to Dipper. Mabel clung to Kevin. Stan and Ford kept eachother a healthy arm's length away.

Something had happened, alright.