I'm kicking myself for not bookmarking this fic, but it sounds like this one (hopefully someone will know the name/link!): Dean and Sam are killed by Raphael, who steals their souls before the reapers get there. There's a scene in part one, after Bobby finds the boys and berates Cas, where Cas is torturing an angel for Raphael's whereabouts, and I'm fairly sure that Balthazar shows up at the end of the scene.
The entire fic is 4-5 parts. Does this sound familiar?

I'm 90% sure this fic is called "Come Hell or High Water"

edit: someone below me figure it out first!

Edited 2012-08-13 11:31 pm (UTC)

Is it Hell or High Water by electric_ink? Summary: Wherein Dean and Sam are killed by forces unknown (again), and Castiel is willing to do just about anything do bring them back. However, things aren’t quite as straightforward as they seem, and the civil war in Heaven reaches an unexpected climax when Raphael shows his hand. A story about faith, morality, and the ultimate cost of free will.

http://ink-electric.livejournal.com/3359.html

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