Timestuck au where 80's Ford gets himself stuck in the future, or even funnier, he just got dragged to the future when the twins appeared outside of his house. Maybe he reached them just before the time tape fritzed out and brought them back to the present. Dipper and Mabel are too far into their own back-and-forth issues to bother with their young Grunkle at the moment so Ford is left to grasp the realization that he just time traveled due to two kids. And he's currently standing in an unfamiliar environment without any of his tools and Journals, in a t-shirt and socks.
He watches as one of the children with the time-travel device disappears in a flash of light and the other remains at the totem pole, knocking her head against it.
Hm. This may be an issue.
Awkwardly, Ford shuffles his way to the edge of the crowds, straightening his glasses and looking around. It seems he's found himself in a sort of fairgrounds, based on the games and rides scattered around. He doesn't recognize any of the people here, expectedly, and while his curiosity is killing him, he doesn't want to wander too far from possibly the only people who can return him to his correct time.
Ford wanders on the edge of the fairgrounds for most of the day, peeking in on the girl at the totem pole occasionally. He does consider approaching her, but he knows he'd most likely mess up that social interaction. He's never been the best at comforting people, especially children.
At one such check, he startles to find her gone. He nearly begins to panic before he spots her and her brother(? They look exceptionally similar to be anything but siblings.) with a pig near the dubiously-built ferris wheel. He can't see the device they had earlier in their hands, so he's about to walk up to them when a older man beats him to it.
The man looks enough like Pa, with the Order of the Holy Maceral fez and suit that Ford swears is packed somewhere in his attic at home, that he's already thrown off-guard. And then the man speaks, and the voice sounds far too similar to-
The man doesn't respond to his voice until the children turn to look at him. Only then does the man turn as well, and then freezes and goes ghost-white when they lock eyes.
"That- that's not possible."
Ford, now incensed and confused on the idea that Stanley has planted himself in his town, storms forward to demand an explanation.
"Stanley, what on Earth are you doing here? Have you seriously followed me all the way to Gravity Falls? Are you here to invade on my research, I've barely settled in! Are you here to ruin my future ag- again? Um."
It's only after he's gotten up into his suspiciously silent brother's face that he remembers; he's in the future. Very far in the future given his brother's grey hair, and it is very much a possibility that they'd made up by now. Surely they can't remain angry at each other forever?
The longer Stan goes without speaking, the less confident he feels, and the more embarrassed he becomes about his outburst. He has no way of knowing the condition of their relationship and situation, he just took the first opportunity to lash out at his brother.
"Stanley? I thought your name was Stanford."
Ford jumps at the reminder of the children standing right next to them and looks down to see twin pairs of eyes scrutinizing them both. He swallows and tucks his hands behind himself nervously, turning his eyes away in an attempt to evade their focus.
"Well, um, yes. My name is Stanford Pines, and I'm a researcher here in Gravity Falls. Ah. Assuming that's where we are still. I hadn't considered spacial displacement, although there must be some involved. We were just outside my house when you brought me here, so-"
Ford startles by a hand brushing against his arm. When he turns back to his brother, Stanley's eyes are flicking over his face with a sort of desperation, like he hasn't seen him in a long time. Alarm flares in his mind when he notices a shine appear over them.
"You're... You're real..."
Ford suddenly, violently, feels like something has gone terribly wrong.
Ford learns that the children are his great niblings, Shermie's grandchildren. It does explain the uncanny resemblance that they have to his and Stanley's childhood appearances. They explain that they were sent to stay with their great uncle Stanford for the summer, presumably the old man they'd spent a few weeks with already. Ford had originally assumed he'd just gone on a research trip shortly before the children had brought him here and him and Stan had pulled the old twin-switch. There's just one issue with that hypothesis.
The children do not know Stanley. They have never even heard of Stanley. As far as they are aware, their family has only ever spoken of Stanford as the youngest of two sons.
On top of that, the more he looks, the less he finds. There's only a few pictures hung on the walls, and they only ever depict the one man and occasionally his employees. No sign of a twin at all.
Ford has to sit down and reconsider the possible causes for this discrepancy. His hands itch for his Journal so he can write down his thoughts and observations. For now, he has to survive with his mental notes.
His first consideration is that Stanley has taken his place for some reason, but that doesn't explain why he'd never be mentioned even in passing. And surely his childhood had come up at some point in time? There's rarely a picture before graduation where one of them was alone in one. He writes that one off as unlikely.
The second is that he didn't time travel, but instead jumped to a different dimension. While it would explain the lack of a twin, if Stanley and he had never split into two separate people. Unfortunately, it would seem that Stanley was the dominant genetics given the lack of a sixth finger and his overall habits. But that doesn't explain "Stan's" reaction to his appearance. He hadn't acted like someone seeing a younger version of himself, but like Ford was someone he hadn't seen in a long time. Or knew he'd never see again.
The thought sat heavy in his chest and had dragged forth his last hypothesis. One of them, most likely Ford himself, had died early on in life. Perhaps even before the science fair. He doesn't like the idea, but it's a high possibility, given how Stan keeps his eyes trained on him like he'll disappear if he looks away. He keeps tapping his hand against Ford's arms and shoulder, like reconfirming to himself that he's not an apparition.
But that doesn't explain why this man is called Stanford. Surely Stan wouldn't steal his name after his death, he'd never forgive himself. Especially at a young of an age that he believes the death happened. Although, depending on how young they would have been, their Father might have had a hand in legally changing Stan's name to the smarter twin's as some irrational hope Stan would take after him once he was gone.
He runs with this train of thought before it is aggressively derailed when Stan nudges him again. This time, something about his hand caught Ford's eye, and he snatches the man's wrist before he can pull away. Ford feels his face drain of blood as he inspects the long scar in the middle of his hand, reaching from the connecting tissue all the way down to his wrist. He flips the hand over and finds it continues on the palm. Ford grabs the other hand and finds an identical scar on that one.
When he presses their palms together, his worst fears are confirmed. The scar lines up exactly where his extra middle digit is. A botched surgery that removed the entire segment from the hand and closed up the space between the middle and ring finger. Both hands.
He looks up to find guilty eyes, filled with sorrow and regret.
"You... Wh... But then..."
Stanford sighs wearily, taking him by the wrist and moving to leave the house.
"There uh... There's somethin' I should show ya..."
Ford follows his future self numbly, horror creating a clog in his throat as he realizes the implications of this change of events. The man in front of him is him, not Stanley, and he'd at some point gone through with the procedure to remove his oddity. The scars are old, but not stretched like they'd be if it happened from a young age. Removing his fingers was his choice. And with all of that...
Tears are already forming in his eyes when they enter Gravity Falls' cemetery.
Stan leads him to the far corner of the courtyard, behind a hill like the graves are being hidden. Stan walks with a focus, following a path he's likely taken many times before. They walk past nameless headstones, cracked and overgrown with neglect. There's one in the dark corner, just on the property line.
That's it. Nothing else is written on the headstone. Not even his full name.
1982. That's barely 4 years in the future. They weren't even 30 years old.
"Ma paid for the grave, but with her savings tied in with Pa's... I mean, you know how he is with money."
Where would Ford be, when his brother died? Would he still be here, writing in his Journals and naively living life to the fullest? How long would it be before he knew his twin had died? Did he feel it? Would he feel it when Stanley takes his last breath?
Is that why Stanford removed his fingers? Is that why he acts like Stanley, goes by his nickname? It must be. He can already feel the grief tearing at his heart, seeing his brother's dead body must have done significant damage on his mind. And it would explain how Stan looks at him, they must still look exceptionally similar. They're twins after all.
Some brother he turned out to be.
Stan is talking to him, saying something about a car crash and the store he'd turned his house into. Ford doesn't intake any of it. There has to be a way to fix this. He'll need to go back to his own time eventually. He can fix this.
He won't accept failure. Not with this.
Or: Through a series of misunderstandings, Ford thinks that he spiraled after Stan died young and Stan thinks Ford's gone quiet and hyper-focused because he's preparing to stop the portal incident. Because Stan was explaining literally everything that happened when they were at the fake grave, Ford just wasn't listening to a damn thing he said.
Maybe Ford is overlooked by the Time Police for a while because they're busy handling the other time anomalies that the twins caused. Stan probably gets Ford to help with the portal too, while Ford thinks it's a giant time machine that could send him back home.
Everything goes a bit sideways when actual future Ford comes back out of the portal and immediately picks a fight with Stanley, and then nearly shoots Ford because he thinks he's the Shapeshifter. But now Ford knows how Stan felt when Stanford went through the portal because he was absolutely ready to raise hell to keep Stan from dying in his time, so he's kind of at odds with both Stanley and Stanford for entirely different reasons.