A Study in Madder (Sherlock/Merlin--the shows, not the characters)
Here's the fic I wrote for 
crossovering. It was hard as hell to write, and I'm not sure it was worth it. But I've now posted more Sherlock fic to AO3 than SPN fic, so there's that.
A Study in Madder (6974 words) by ariadnes_string
Chapters: 1/1
Fandom: Sherlock (TV), Merlin (TV)
Rating: General Audiences
Warnings: No Archive Warnings Apply
Characters: Sherlock Holmes, John Watson, Greg Lestrade, Mycroft Holmes, Anthea (Sherlock), Merlin (Merlin), Arthur Pendragon (Merlin), Gaius (Merlin), Uther Pendragon (Merlin)
Additional Tags: Episode: s01e01 A Study in Pink, but in Camelot
Summary:
When John Watson returned to Camelot after a long absence, he made three vows.
The first of these, to turn his face from violence, he broke almost immediately. Mere days after re-entering the kingdom, he found himself standing once more over a dead body.
crossovering. It was hard as hell to write, and I'm not sure it was worth it. But I've now posted more Sherlock fic to AO3 than SPN fic, so there's that.
A Study in Madder (6974 words) by ariadnes_string
Chapters: 1/1
Fandom: Sherlock (TV), Merlin (TV)
Rating: General Audiences
Warnings: No Archive Warnings Apply
Characters: Sherlock Holmes, John Watson, Greg Lestrade, Mycroft Holmes, Anthea (Sherlock), Merlin (Merlin), Arthur Pendragon (Merlin), Gaius (Merlin), Uther Pendragon (Merlin)
Additional Tags: Episode: s01e01 A Study in Pink, but in Camelot
Summary:
When John Watson returned to Camelot after a long absence, he made three vows.
The first of these, to turn his face from violence, he broke almost immediately. Mere days after re-entering the kingdom, he found himself standing once more over a dead body.