Blue Is My Saving Grace

Castiel is a doctor in the Mercy Medical Center ER, where he loves his job in helping others. Everything in his life hadn't exactly been a smooth ride, but he liked his life, liked where he ended up. But on a fateful day, he gets a major migraine, and things afterwards will never be the same for him.
Sam and Dean are currently in Sioux Falls, deciding to stay behind a little longer after dealing with the Leviathans and giving Bobby a proper hunter's funeral. They deserve a little R&R. But as is the Winchester way, they can't stay away from the world of hunting for long, and soon get word of a case close by that has them scratching their heads.
Featuring demons, hellhounds, monsters and, probably the biggest challenge they face, their own stubbornness. Our beloved characters are thrown into a plot with mystery, adventure, plenty of mythadventures, and even some adventures they weren't aware they needed; all along a journey to stop the rising of a possible Apocalypse 2.0.

"What if, instead of Kevin becoming the next prophet, what if it were Cas?" said my brain. Thus this story is born.