The Time Traveler 's Brother by AmyPond45 (AO3). Rated R, Sam/Dean, 54k words. Summary: Dean 's life is turned upside down the night his mother dies. But that 's also the night a mysterious grown-up version of Dean 's brother first appears in his life. While Dean grows up, "Old Sam" is often there, especially when Dean 's father isn 't. As Dean learns what the future holds, he begins to question everything his father has taught him about who he is and what he is supposed to become. Can Dean find a way to save his little brother from his own future?
ao3.org/works/3416087
my thoughts: Beautifully written. I 'm not a huge fan of younger!Dean and older!Sam but this author keeps the affectionate lilbro and bigbro sibling dynamic despite the warping of time. A magical read that breaks your heart but still feels like a satisfying+happy ending. If you like this fic, you 'll probably like Break on Through to the Other Side (ao3.org/works/1457095) which has some similar elements to this one. This fic 's also in my movie fusions reclist .

You Can 't Go Home Again by Amypond45. PG-13, Sam/Dean, 27k. Summary: Sam and Dean discover evidence that they time-traveled to 1983 to help their Dad and their younger selves right after their mother died. Then things get complicated.
ao3.org/works/2065908
my thoughts: Okay, it 's an inescapable fact that Amypond45 is the go-to choice for fics where canon!Sam+Dean meet either themselves in a different timeline or themselves from separate dimensions (so apt for season 15; I hope she 's lovin ' it wherever she is out there!). This fic stays with me bc it was writter like an outsider POV looking at adult Sam+Dean... but the outsider POVs were Sam and Dean as kids! Whaaaat. I know. It 's awesome. If you like this fic, you 'll like charmer & gentle by askance (rated G, Gen, 3k words, ao3.org/works/4932184).

Afterimage by paleogymnast. Rated NC-17, Sam/Dean, 27k words. Summary: "If you had it to do over again, and you could change everything, would you?" When all appears lost, Dean Winchester—battered, weary, guilty, and alone—is given the opportunity to travel back in time and live his life over again with the promise that if he makes the one choice he was too afraid to make before, he will be able to change the future, and avoid the loss of everyone he ever loved and everything he fought for. But how? After all, he knows time can 't be changed… But with the help of a mysterious entity, who may or may not be the actual God of Time, Dean discovers time can be rewritten.
Armed only with the ghosts of memories from his former life—afterimages of rewritten time—but not really understanding the gift he 's been given, the new Dean, an impossibly young 27-year-old hunter, once again turns to his estranged brother when their father goes missing. But when he takes a chance on forbidden love, will it be the key to saving the universe and averting the apocalypse, or will it only bring about the end even faster?
ao3.org/works/4504065
my thoughts: Holy crap this author 's writing hijacked me the last week of October while I was still trying to churn out a lot of written work). I absolutely loved this story, loved how Dean pressured himself to admit his feelings for Sam during Bugs, how the author described/framed Sam & Dean 's relationship, and plot-wise how information on seasons 4 & 5 filtered into seasons 1-2ish Sam/Dean. It filled me with so much hope & happiness to imagine them besting their destinies like this with the help of Kronos. Also I'm such a sucker for soulmate tropes & loved how paleogymnast let Bobby and Missouri be cool about Sam/Dean.

Another Go Round by KassandraScarlett. Teen and Up, Sam/Dean, 21k words. Summary: Someone sends Dean back to 2009, with a mission: change the past, change the present, so the apocalypse never happens. Dean leaves behind a Croatoan-ridden world, only to stumble into the one person he's always loved more than anything else. Or: Zachariah doesn't send Dean to 2014. Instead, Chuck sends the Dean of the future to 2009.
ao3.org/works/23284600
my thoughts: The aaaaaaangst in this one was so, so amazing. I loved how kassandra had future Dean, this savage post-apocalyptic warrior, realize he was in the past, pre-apocalypse, he's got Sam, and everything falls away and he gets to love Sam again. And Sam, how desperate he is during this time period in canon for Dean's affection... 😭😭😭 ugh, this was so good, y 'all. This fic was in my 2020 Variety Pack reclist on tumblr & my alt seasons 4 & 5 reclist