The weathered "CONDEMNED" sign rattled softly as Mabel pulled against the break in the rusted chain link fence, allowing Dipper to pass through. In the pitch-black of night they felt their way through an overgrown thicket, before emerging into an open, brick arcade. The arcade enclosed a modest courtyard that lay before a strange, shuttered house unlike anything Mabel or Dipper had seen before: narrow and tall with an asymmetrical tower and a decorative style somewhere between Second Empire and Northwest Coast Indigenous. Dipper looked nervously at Mabel, who wiggled her fingers and pursed her lips, miming a ghost's moan. He rolled his eyes and pulled a small crowbar from his backpack. While Mabel held a flashlight on the door Dipper methodically loosened the boards that had been nailed over it. With the last board gently leaned against the house Dipper reached for the knob and turned. It clunked dully and the door creaked open.

The house smelled like something between a used bookstore and an auto repair shop, a mix of yellowed pages and petroleum oils. The study they'd entered was packed with papers, boxes full of spare parts and above-all clocks, dozens of them. Dipper cleared a space on a stained worktable and took the Journal from his backpack. "Charles Jules Bontems," he said, flipping through the weathered pages. "1870-1935. At the turn of the century Monsieur Bontems was regarded as one of the most talented clockmakers in Paris and was a close personal associate Charles Richet, noted physiologist and parascientific researcher. Bontems believed that ectoplasm was a kind of disembodied vital force, which if harnessed could interact with the physical world through mechanical constructs. After a bitter dispute with his mentor Richet, Bontems immigrated to Gravity Falls where he built and repaired clocks to finance his research. I have found no indication that his research yielded any practical results, however, there were rumors that a great treasure was hidden somewhere in his house." Dipper stopped and turned to Mabel, who was nosily rummaging through a box. "Are you listening?" he asked, annoyed.

"Of course I am Dip. Girls are better at multitasking than boys. Check it out." she lifted her head to reveal a pair of earrings that hung well past her knees which she'd fashioned from watch parts and paperclips. "I call them 'Gearrings.'" she said, twirling a bit to show them off.

"Aren't those heavy?" asked Dipper, squinting at his sister's strained lobes. "And wouldn't they get caught on stuff?"

"Dipper," sighed Mabel, "I'm afraid my fashion sense is a little too sophisticated for you to understand." Dipper took one the earrings into his hand and looked at it thoughtfully, before nonchalantly and giving it a small tug.

"Toot."

"GAAA! Let it go!"

"Ok, now I can see the appeal." he laughed. Mabel scowled and took them off.

"Alright 'Mister Good Ideas' what's your plan for finding the treasure when no one else has?"

"Mabel, do you know how many Sibling Brothers books I've read? There's always a secret switch or a candelabra-lever or some sort of false-book-safe-thing. Trust me, I'm an expert."

"Yeah, that's totally not a rationalization for committing to a book series that has basically sold you the same story two hundred times." Dipper handed Mabel a headlamp from his bag.

"Shows what you know," he said defiantly. "It's more like one hundred and eighty nine." Dipper Zipped up his bag and dramatically adjusted his hat. "Ready?" he asked.

"Are you serious? Give me a mustache and call my Schliemann, I was born ready."

The twins made their way from one room to the next, the old floors groaning with each step. The rooms outside the study were largely empty, and it wasn't long before they came across the door for the tower. The four-story tower had been completely hollowed-out, save for the top floor, which was accessible only by a narrow ladder set into the wall. After a cautious and creaky ascent Dipper pushed open the trapdoor and the two crawled into the strange space.

Besides a small study niche beneath the only window the room was enveloped by a tall, elegant, circular bookshelf, packed not only with books but also a collection of sophisticated clockwork automata in various states of assembly. Examining the shelves, Mabel was instantly transfixed by one creation in particular. On the high shelf there was what appeared to be a young boy holding a quill seated at a desk with a pad of paper and a small inkwell.

"He's so…tiny." she said as she approached the shelf. Dipper pressed his foot tentatively against what felt like a rather weak floor.

"This looks really promising…" he said, turning his attention to the opposite bookshelf, unaware that his sister was already halfway up the other. "…but let's make sure we're really careful."

Mabel reached the top shelf and examined the figure intensely. Arranged carefully next to the desk was a sealed bottle of ink and a brass key. Mabel uncorked the ink and poured out a small portion into the well. She felt for a hole in the figure's back, and with laser focus she gently inserted the key and turned four times.

The boy quietly whirred to life as hundreds of minute gears, rods and springs began their delicate interplay. The boy's eyes and head followed its hand as it dipped the quill into the well. It smoothly lifted the implement and turned back to the paper, where began to write in immaculate calligraphy.

"Mon…Enfant…Mécanique…" Mabel mouthed, oblivious to the sagging shelf on which she stood. "Zero…five…zero…seven…one…nine…three…three." The child ceased moving and Mabel carefully lifted the small sheet. Just then, Dipper completed his examination of the opposite bookshelf and turned to see his sister's precarious position.

"Mabel, what are you…Mabel look out!" The shelf beneath her snapped and she plummeted like a stone.

"AHHH!" Mabel crashed through first one, and then another set of weakened boards, her hand barely managing to catch a wobbly crossbeam as she fell. Below her, books and broken wood clattered loudly over the tower's stone base.

"Help!" she yelled, grasping for another handhold.

"Hold on!" said Dipper as he crawled over to the hole and extended his hand. Mabel reached up for him when her headlamp passed over something sliding towards her. In the space between the floor and the ceiling Mabel could see a rapidly descending wooden box with some sort of dial combination lock.

"Dipper!" she said breathlessly. "I found something!"

"Forget it!" he pleaded. "Grab my hand before you fall!"

"Just another second…" she said. With her free hand Mabel caught the box just before it slipped through the broken ceiling. She tucked it under her arm, which she pressed against the edge of the hole to steady herself. She looked back up at Dipper.

"Mabel, you'll need both your…" before he could finish Mabel pushed off with the arm holding the box and slapped Dippers outstretched arm with her other hand. She gripped him desperately, the entirely of her weight pulling on his arm. "URRR!" Dipper groaned, straining against the burden. With all his strength Dipper guided Mabel's arm to the edge of the floor, which she used to pull herself up. The two lay on the floor and panted next to one another before Dipper's profound anger caught up with him.

"WHAT WERE YOU THINKING?!" he demanded, "That was an incredibly irresponsible thing to do!"

"Incredibly irresponsible…" said Mabel as she held out the box. Shining brass letters that spelled out the word "TRÉSOR" had been inlaid into its polished surface. "…or just incredible?"

…