What would have happened if Sirius had not run away from home? Perhaps the best way to find out is to take a look at the life of his younger brother: Regulus Black. (Formerly titled I, Regulus).
James has always had a thing for the lovely, if not snarky, Lily. But when he becomes an auror, his dog-like devotion will be put to the test when he discovers that the angelic Lily's secretly a deatheater. Parody JPLE
Why does Peter Pettigrew sell the Potter's to Voldemort? This is the story of Wormtail begining right before he becomes the Potter's secret keeper. Formerly titled Until the End.
This is Sirius and a bit of Remus's pov of what happened in the department of mysteries.
Sirius has wasted away in Azkaban Prison for twelve years, nearly mad with thoughts of revenge and pain. But when Cornelius Fudge gives him a newspaper with a certain fallen marauder on the cover...