It was the small things that mattered. The ticks on a list that made up the breadth of a wider topic, something larger to be seen, but only by those with the right eye for it. The people of Gravity Falls were dumber than rocks, Stan was sure, but he'd travelled states and crossed seas and there were few things that could slip past his vision, bootless as it was.
It began with his brother. Twitchy, pulling at the rims of his coat jacket, with flit movements to his eyes that suggested he was searching for something. For a while Stan was hard-pressed to think of what, but his memory probed him soon enough – he was searching for gold, and it wasn't the kind that would bring a man riches.
The more familiar he became with Ford's behaviour, the more he picked up on Dipper's. Mabel's, too, but to an extent that he felt nestling her against his side and flicking on the television would nurture enough that he could plan ahead. For her brother it was different; difficult. Dipper's mind galloped faster than a racehorse. No pixels on a screen would slow its stride.
"Can I use your card, Grunkle Stan?" he asked one afternoon, when the markets had roamed in and set up shops full of relics and candies.
"Hm?" Stan played dumb, but the inkling was already there. "Pretty sure they only take cash over there, kiddo. I don't think they'd even know how to use the machines."
Dipper laughed, hollow, and fiddled with the paper in his pocket. "Yeah, you're right. Sorry."
When the kid had drifted back to his sister, Stan reached into his own pocket and unfurled a dollar bill. The eye peered back at him. If he crinkled the paper just right, it curved upwards in a smile.
He monitored them for a week. It was hard work, watching people, but not for his family. He didn't need to keep notes or hatch schemes for them. Ford sectioned himself off to the basement, focusing on his books, and Dipper withdrew more and more from family activities. The creases in their eyes that had once indicated smiles became deep, dark and permanent. The adventurous glimmer now a paranoid glow.
He'd defeated the big bad; made the plenipotent deity kneel before him and beg for his own life, only to serve up the most well-cooked knuckle sandwich he'd toasted on the stove. Yet, there his family was, continuing to be terrorised despite the only remnants of the triangular nuisance being a half-cracked stone statue buried in the ground.
Well, Stan decided, that wouldn't quite cut it.
The Mystery Shack stayed closed for two months afterwards. With Soos's quick hands and Stan's own eye for interior design, windows were easily excavated and replaced, tapestries pulled apart and thread into newer, brighter patterns, and furniture moved about to make room for a more homely space. In the meantime, he sent his family on a cruise – not only was it relaxing, but there were never any eyes out on the open sea.
When they came back, it was to a house devoid of any leering stares. Carpets previously adorned with shapely deities now sported unicorns, gnomes and other mythical beasts. The windows were clear of pattern, allowing the light to shine through and warm their skin. It wasn't an immediate fix, nor a permanent one, but in the coming days Stanely saw more smiles and more laughs from his family than he'd seen since his memories had come flooding back.
Sitting out on the porch, watching the two kids throw ketchup-filled balloons at eachother, he flattened a dollar bill and laid it across his knee. A small, comical triangle stared back. His simplest depiction; his least threatening look.
The only way they would ever see him again.