I've been searching and searching for this fic (lost in the bowels of my computer), it was a WIP last I checked (year or more ago?) Hopefully y'all can help me!

Dean and others are fighting against a demonic apocalypse. A zombie disease is wiping out people everywhere-Dean is affected and becomes a full-out zombie. I think he kills some Hunters (maybe Jo?) who don't realize he's been zombie-fied. He becomes a mindless killer, part of the zombie hoard. However, something happens and he recovers, still looking like a zombie but now in control, and begins to remember stuff from his non-zombie life. His recovery is taken as a sign of hope by some of the uninfected, but demons and zombies are still run around, killing people and endangering Dean. Dean is trying to figure out what the heck happened to him and the world while he zombied-out and his possible role in stopping the apocalypse...can't remember where Sam fit in with all of this.

That's all I remember, ring a bell with anyone? I'd be so grateful if you'd direct me to what hopefully is a now completed fic. Thanks!

FOUND! Thanks kassidy62, "Old Bones Upon the Mountain Shake by indiachick"
http://archiveofourown.org/works/815643

Not updated in a while, hopefully will be added to and completed soon!