Hello, little skulls!
So, I lost this delightful fic, probably well known, in which Sherlock comes back after Reichenbach and things happen and in one of the final chapters/scenes they are with Lestrade, arresting the suspect and all that, when suddenly someone almost shoots John and it's just thanks to Sherlock that the bullet grazes John's shoulder/arm and nothing else; anyway Sherlock goes a bit mad and runs after the guy and he's actually pretty set on killing him after beating him to almost death, but then John goes after him and tells him that Sherlock promised to be home every night so he's not allowed to go to prison otherwise John would have to kill someone too in order to stay with him and he's not sure they allow conjugal visits and so on.
And I don't have a gift for synopsis, I fear XD
It's a bit of a mess, so double thanks to anyone who will be so brave to try and find a plot in THAT.
;)
EDIT:
Found by
piplover"Bedtime Stories" - Link in the comment section.