Many years from now, after the Gates of Hell have been closed permanently and the angel has fallen to be with his man, a television writer stumbles upon an obscure old series of books.
Despite the production company searching to their best ability, the author, a mysterious "Chuck Shurley" is not to be found, neither are next of kin to claim copyright or royalties. And so Supernatural is filmed.
At first Dean is adamant at getting the show stopped; after all he has earned his privacy and peace.
He suggests to Sam that they come forward and claim copyright, perhaps they should sue the bastards, but Sam patiently explains that it'll be futile, and Dean begrudgingly accepts. But he'll definitely never watch the stupid show.
Nor will Sam, it's their silent agreement. And they're older now, each with their homes and families - it's more likely that if a younger fan saw Dean and Cas together now on one of their nature walks, they'd think "grandpas" rather than "badass hunter and butt kicking angel".
But it's fine with Castiel, who has always been old, and Dean who never expected it.
Sam keeps himself busy.
Often he drives to the bunker just outside town. There he is occupied with indexing the vast collection of knowledge left by the Men of Letters.
Most of it has become otiose with the closing of the gates, but Sam still feels a sense of responsibility to keep everything preserved and in order.
And of course he can't help snooping around his wife's successful antique's shop, to her great exasperation. He mutters something about "cursed objects", and Sarah just rolls her eyes.
Still, one day where they're sitting in Castiel's garden and enjoying a beer (and it truly is Cas' garden, for he's the one tends to the flowers with a fierce protectiveness), Sam turns his eyes to the heavens and sighs:
"You know, my hair was never that long", and Dean replies with a sarcastic "oh?" before Sam taps him gently on the shoulder.
They sit in silence for a while, birds chirping away, before Dean states:
"Cas is definitely better looking than that two-bit actor."
Sam smiles. "Of course."
Sarah too can't help her curiosity, and is disappointed to learn that her character has been reduced to a whiny damsel in distress.
She complains to Charlie, who has never lost her passion for popular culture and feminist discourse. They talk for a long time.
Afterwards a broadly smiling Sarah finds Sam hunched over a book - she grabs him and kisses him.
"If only those writers knew that I'd be your endgame!" she says, before kissing him again.
Sam returns the kiss, stooping down and cupping her face in each hand, happy because Sarah is happy.
It happens that a series of strange posts, written in all caps and full of exclamation marks, appear on a popular Supernatural message board. The poster claims that there are some striking similarities between the characters on the show and their own family.
Most call troll, and those who demand proof doesn't receive it, because the poster never returns.
But at the Winchester-Blake home Sam has a talk with his 14 year old daughter, Jessica Mary, which stretches long into the night. There is disbelief, tears, more disbelief and then hugs.
The next morning Jess looks at her family with renewed admiration and respect, and also with a sense of pride. Sam has promised to take her to the bunker to show her some of the secret knowledge, for Jess too is a legacy.
And she never complains about taking out the trash again.
Charlie regularly calls Dean, excited to tell him about the online discussions that have been blowing up ever since Cas' first appearance. Specifically the ones about Dean and Castiel's obvious sexual tension and true love.
"They knew it way before you did," Charlie teases.
Dean is huffy at first, protesting that he doesn't watch the show.
"Yes you do, you grumpy old geezer," she replies with love in her voice.
One night, when Dean thinks he's being sneaky by catching the late night reruns, Castiel joins him by his side. Watching the show together, Cas can now, with his human understanding, explain his thoughts and motivations at the time, scene after scene.
And Dean, he can feel the tears well up in his eyes as he relives his frustration and their battles, knowing now that there is a happy ending after all; that he can reach out and touch Cas, that they're holding on to each other.
And he thinks maybe, just maybe, the show isn't so stupid after all.