Drip. Drip. Drip. Pattern echoed through the musty warehouse where blood started pooling on the concrete under Dean's arm.
His blade ended up behind... That thing. No way of reaching it. Not with the wounds he just got.
"So what happens now. You gonna finish the job?"
Black eyes stared back. No response.
"You just gonna stand there and watch me bleed to death, huh? Finish the job!"
The look was unnerving. It went through Dean's chest and dug around until it found his heart and then clenched.
He bit his tounge.
"You know, the person you used to be would be gracious enough to actually say something to his best friend after cutting him up, not just stand there like a demonic fuck."
"No response, huh." His sight got foggy.
... From the blood loss.
The black eyed thing that used to be Cas didn't even cock its head in acknowledgment of hearing anything Dean said. Or it did hear. It just didn't care.
The clench got slightly tighter.
"Typical. You spend months searching for the guy and a way to help him and when you finally find everything and sacrifice a fuckton of shit to do it, he won't even acknowledge your attempt to let him explain himself. Thanks, Cas. Aces." Dean bit out through pain. He leaned back on his knees and laid his back against the wall, one hand holding his bleading arm and the other holding his guts where they're supposed to be. Inside his body.
"You know what I still don't get is what the fuck happened five months ago. You were fine, we. Were fine." As much as they could have been, considering the circumstances.
He coughed and blood sprayed his chin.
Seven months ago they'd caught a wiff of a werewolf case in New Orleans, people torn apart in the night by a wild animal, possibly a wild dog. So all three of them drove down and got royally screwed. As it turned out, it was a wolf like monster, just not the one they prepared for.
The rouge hellhound got to Sam first. He was fast enough but with the wrong weapon. And Dean couldn't react on time.
Cas reacted by jumping in front of Dean and taking the next bite meant for him before killing the mut with his angel blade.
Sam bled out in the car on Cas's unconscious lap, maybe three minutes after hightaling it towards the motel. Or at least Dean figures it was three minutes. During them Sam stopped crying that it burns, it burns, Dean, oh God, Dean help me, please, it burns. Venom was too strong for Sam to bear.
He got Sammy home. Put Cas together the best he could at that moment and left him feverish in his bed to take care of his baby brother.
Dean suspected it was the venom in Sam's bloodstream that made the body burn as fast as it did. Three hours and all Sammy was was a pile of ash and a painful memory.
And all Dean had had left then was Cas. It was a tough month after that.
Cas woke up four days later, weak and unsteady, but alive. Said it took a while to get it out of his system. What little grace he'd had left was fried.
Dean doesn't remember those four days. Just the smell of whiskey and antiseptic and silence.
He told Cas what happened. They got drunk together with Dean falling apart on the kitchen floor, sobbing on the angel's chest. That's where they passed out.
They unvoicedly decided to quit hunting for a while. Both of them needed time to mourn and learn how to live with what happened. And they were doing good. Promised each other not to drink their sorrow away unless it was together. Except neither wanted the other to get shit faced as a way of dealing, so neither did.
They cried. They talked. They tried to adjust. They were doing good.
And then Cas started to act weird, a month and a half after Sammy died.
Small stuff at first.
He stopped sleeping. Dean heard him walking around the bunker a few nights in a row and thought his grace must've gotten better for him to not sleep anymore. Except he didn't tell Dean anything. When the hunter brought it up, Cas denied it. Said he went to sleep every night and woke up in the bed in the morning. So the sleepwalking was the the first sign.
Over the next few days, he started zoning out. Then seeing shapes that weren't there. Then one day he cut himself on his own blade while attacking thin air with Dean trying to restrain him. His blood came out as runny black goo.
As it turned out, Cas didn't in fact get the venom out of his system. It ate at his grace and started filling out the hole it left behind.
When Cas realized it, he pushed the blade into Dean's hands and spread his arms.
"Dean. We don't know what's going to happen when it destroys my grace entirely" Cas's voice hitched.
"... and I don't want to find out."
Dean tossed the blade away with a curse.
"We'll figure something out."
Obviously, they didn't succeed.
From then on it just got worse.
Cas started forgetting where he was or who he was with.
Then finally, he forgot Dean was a friend and tossed him into a shelf hard enough that the hunter lost consciousness.
When he woke up, Cas was gone.
No note, no nothing. Doors of the bunker left wide open.
It took him two months, six witches, two demons and one old druid to get his hands on a purifying ritual for supernatural creatures.
Jody called. Told him about a possible demon slaughtering random people across the states. Witnesses described a man in a tan coat with black eyes.
Sulfur was found on every crime scene.
It took him another three months and a fuck ton of possible leads to finally track Cas down.
And there they were.
Cas a demon, or as close to one as he could get. And he got there by protecting Dean from getting killed. Oh, the irony, considering Dean would probably die in a few minutes from Cas's own blade.
Dean didn't even try to find it in himself to care.
"There's nothing to explain." Not-Cas monotoned.
"Oh, it... speaks." Dean tried to jab but considering he couldn't even breathe properly it fell pretty flat.
"If I had stayed I would have killed you. So I went to kill someone else." Finally Cas cocked his head. "Looks like that'll make no difference in the end."
More blood sprayed Dean's lips.
"C-Cas. I can save you. We. Can save you." His torn stomach argued that and stung even harder. He grimaced, but kept talking.
"In that bag. All the i-ingredients... We need."
Cas turned his head slowly to the bag Dean had dropped when he tried to tackle the ex angel upon his arrival.
Labored breath.
"Please, man. You... You said you didn't w-want this." Another cough, more blood splatter.
"Let me help you." he wheezed out.
Cas turned back to the hunter.
"Oh, Dean. You can't even help yourself."
He paused like he remembered something, then a slow, small smile that looked wrong on his face pulled at his lips.
"You couldn't even help your brother."
The clench around Dean's heart closed its fist completely and pulled it out. He closed his eyes.
"What makes you think this situation is going to be any different?"
His voice sounded closer.
"It won't be." Definitely closer.
Dean's mind already swam, but he tried to focus a little while longer. He owed that much. To whom, he wasn't sure.
Wet metal tapped the underside of his chin. He opened his eyes to blurily see Cas crouching in front of him with the blade and black eyes.
"It won't be." Cas repeated.
Dean took a deep breath. He never imagined this was how he'd go down. Some twisted part of his dying mind whispered at least it was someone I loved that did it.
Then a gun shot cracked the air and Dean vaguely recognized Jody's and a few other voices shouting.
If he wasn't on the death's doorstep he would have smiled. Cas was right, it won't be different, at least not from Dean's side of the story.
But maybe Jody and the girls will succeed where he failed and cure Cas.
That was as far as his train of thought could go before being swallowed by Cas's angry scream and the blinding light of Dean's reaper.