The Arrangements 'verse: Team Free Will meets everyone's favourite angel and demon, and everything spirals from there.A long (90k+) fic by icarus_chained.An Alternate Universe story where sometime post Supernatural episode 5x10/"Heaven and Hell", Dean, Castiel, and Sam run into Aziraphale and Crowley, and (after some initial confusion/animosity) the five of them team up, gaining a few more allies along the way...Note: Arrangements is technically unfinished, due to complications in the author's life; what's marked as the last chapter on A03 is actually a summary of how the final chapters were intended to go. However, it's a very thorough summary, often feeling like it could be a fic in itself, and so the story feels quite complete.
Don't get Aziraphale mad. In particular, if you kidnap his demon, his face will go blank.
Not blank like 'I'm in shock and don't know what I'm doing'. It was blank like 'I've just switched off every emotion that might stop me from doing what I need to do, and mercy and fear were the first to go.'
Suggesting that Crowley might be actually trying to lure Aziraphale to the Dark Side is a pretty bad idea, too. Torturing and almost killing an archangel in front of him isn't much smarter.
Blatant Lies: For a very short time, Aziraphale and Crowley attempt to appear strictly platonic.
Aziraphale: It's a business arrangement.
Dean's inner monologue/narration: ...and 'business arrangement' my cute little ass...
Everyone Can See It: Both Dean-and-Castiel and Aziraphale-and-Crowley. The latter pair initially tries to put on a facade of simple friendship coming from 6000 years with only each other for consistent company, but they fool no one. The first one is initially "simple" UST, but eventually They Do.
Fallen Angel: Castiel, of course, as it takes place during season 5. Crowley, of course, never fell so much as "Sauntered Vaguely Downwards"... or maybe not?
Flaming Sword: According to Aziraphale, wielding it's like learning how to ride a bike... you never really do forget.
Raphael. Deliberately withholding medical treatment for six thousand years solely to give your side a martyr is kind of really dickish.
Nice Job Breaking It, Hero: Said almost by name, though not really a case: after Aziraphale makes a careless reference to the Apoca-Wasn't, utterly horrifying the various people not in-the-know, Crowley points out his mistake.
Crowley: "Nice job breaking the humans. Did you forget what Adam did last time?"
Relationship Upgrade: There are two during the course of the story, and one that happened off-screen: Dean/Castiel, Sam/Gabriel, and to no one's surprise, Aziraphale/Crowley.
Scars Are Forever: Subverted. Gabriel's had his scars for six millennia, but only because Raphael refused to heal them.
Stepford Smiler: Most of the good angels; in fact, the only angels who are more stable and straightforward are like Zachariah.
Not bi-polar, no. Not swinging from cheerful to grim. Just putting the cheerful on over the grim, whenever they could, whenever they could bear it. Even Gabriel, maybe. Putting smiles and cheer and smartass remarks over the knowledge that their world was slowly falling apart around them, and hoping that if they just did it enough, if they just smiled enough, they might come to believe there was something worth smiling about. Not so different from him and Sam, when it came down to it. Not so different from any of them.
True Companions: Both Team Free Will and Aziraphale-and-Crowley at the start of the story; Castiel, Dean, Sam, Gabriel, Aziraphale, and Crowley all end up pretty well attached to each other by the end.
Bobby remains the father figure to Dean and Sam that he is in canon.
What Could Have Been: The last chapter is technically a summary of how the last several chapters would have gone if the author had had time to write them. Though very good in itself, it does make one wish we'd gotten to see it play out over the full length it was originally intended to take...