"There is a destiny that makes us brothers"
http://www.fanfiction.net/s/3599921/1/SPN_Destiny_Verse_There_is_a_destiny

Summery: Just change one thing AU – what if Jess hadn't died after the boys' weekend in Jericho? Story takes place some years later, when Sam is 26, Dean is 30. AU so canon events take place differently, later, or indeed, not at all. Sam is a lawyer and is married to Jess. Dean calls him up needing help because he actually got arrested after the events of Nightshifter.

This one doesn't fit the prompt but is a prequel to the above fic just in case you want it.
"Through a mirror cracked" http://girlfan1979.livejournal.com/31168.html