What it says on the tin. (Including Follow-ups to: Maybe one of these days you can let the light in, and One Of Those Things, and Mrs and Mr Pond..)

“Eternity is really rather boring, John. Mortal life seemed as though it would be far more interesting.” Sherlock is actually the Devil, but he decided to live as a mortal because ruling Hell was boring.

Apparently Supernatural was real, which was presumably why Gabriel was bleeding out onto Richard’s floor. (In which the actors of Supernatural find that reality is stranger and more disturbing than they previously believed, even counting Misha, and an injured archangel discovers that his universe is the subject of a TV show.)

After the final Seal is broken, Dean discovers that he's actually Lucifer. He's not really sure how he feels about that.

When Loki attempts to mind-control Tony Stark in the middle of the Chitauri invasion, he unlocks powerful memories and abilities, and Tony realises that he's something greater and more powerful than he ever knew. And so is Steve Rogers, but that's a slightly different problem.

Two hundred years ago the Winchesters stopped the apocalypse. Now, instead of getting into fights and running amok, eighteen year old Jim Kirk goes to live with his Auntie Sam and learns the family business. Four years later, an angel shows up.

Sam smiles, bright and luminous. "An angel's Grace isn't just power, Dean. It's a part of their soul." An AU 'verse that takes place after episode 5.22.

And how things could have gone differently.

“Your first mistake,” John says smoothly, “was calling yourself Moriarty. It got my attention.” In which Jim is not, in fact, Moriarty.