The air is sweet with death and burn and Cas knows it's all Dean, before he even turns to the man. And when he does, what he sees makes the grace writhe like magma within him.
The glow of the brightest one cannot outshine the darkness. It is black and red and rotten. Crawling up and to the left, on the silver threads of the soul that Cas once sewed and weaved back together where Hell tore at. It's gnawing and scratching with its filthy tongues. It hovers inches from the heart, still extending its claws towards it, trying to reach and grasp and devour.
And it will, eventually.
Soon.
It's got the arm for now, where it began and made its home, from the fingertips to the neck and then higher. It licks at the right eye and it makes the vision askew. It's swirling like serpents, dying embers on the charcoal that used to be light and life and fire.
It's gangrene.
And there, in the heart of that obscurity, sits the Mark. Never seen, but known all too well to the angel. It kicks him in the guts and pumps the air out of him. Hesitation – it cannot be… Yet it is, right there, the destruction, from inside, of what could never be broken in Hell.
"What have you done?" Out comes a growl and it almost knocks Dean off his feet, as his back hits the wall, a fist wrapped around his shirt.
The other palm bruises, fingers bite at the skin around Dean's wrist. His arm held high, the Mark hanging in between the angel and the Worthy.
"How'd you-"
It's all in the eyes: the wrath that befalls him quietly, the hurt that's there to stay. The regret that should be Dean's. And just then Dean's own eyes go wide, like it hit him harder than Castiel's fist could.
The fingers let go.
"It's no big deal." His shrug's met with a bitter laugh, brief and caught up in the throat.
Cas is not looking at him and the darkness, anymore, but it's all still there and it's not going anywhere. It hangs in the atmosphere like an insult. It's cold and it's heavy, it forces the holy away.
Still the holy remains.
"It's no big deal if you miss Hell so much."
Only silence laughs this time and weighs on Dean's chest.
"Come on Cas," still fake lightness and carelessness, "I'll kill Abaddon… Then I'll worry about this." Still headfirst to saving the world. "I'll find a fix."
He still doesn't get it.
"There is no fix, Dean." If he only saw the same as him, if he only felt it. But he doesn't, not yet. "I'm afraid this time you cannot be saved."
The embers howl triumphantly. They've conquered the moment they called dibs, and now, even the old savior declares defeat.
"Well then… At least she'll be dead."
There are maps spread on top of the map table, there are letters and scrolls that fall apart at the touch and Dean's eyes won't rise from them again. Like maybe they could save him, like maybe the Knight's death can.
"How could you do something so stupid?"
"Means to an end."
The answer is quick and rehearsed, though Cas didn't expect any. He's through with reaching, when there's nothing to reach for anymore. Lost is the battle for what he himself fought for in Hell, the brightest, the purest, the righteous. Lost is the battle for what he's loved and thought more precious than Heaven.
"I hope your end is worth your soul."
And the darkness laughs and sprawls and devours.
