(this is my first post to LJ ever so bear with me because I'll probably mess up, even with the guidelines :P)

I'm looking for a destiel fic that I read a few months back that I forgot to bookmark. It involves Cas, Dean, Sam, and I believe Bobby at some point. Basically, TFW has to travel around and find the pieces of Cas's grace (I think it's Cas's, at least, it could be Gabriel's) and I think Cas goes off by himself in the beginning. There's a huge (like HUGE- witches, demons, hellhounds, the whole deal) showdown outside a warehouse at the end where some demon, maybe Crowley, tries to use the grace to power themselves up, but Cas absorbs it, saves Dean&Sam, dies, and comes back to life, totally human. I also remember a specific point about the grace Cas absorbs not being complete, so it could have blown him up or something. The fic is NOT "The Law of Conservation of Energy", which I have read and highly recommend :) Thanks for the help!