A/N: I saw a prompt on Tumblr (I can't remember for the life of myself whose it was I'm sorry if it was yours or if someone much more talented than me has already written a fic using that prompt). So please ignore how terrible my writing is because I'm suffering from writer's block 99.9% of the time and thank you for even bothering to read it :)
Ps: Also, this is placed around after season 9 but I haven't actually finished season 9 or started season 10 so a lot of the canon stuff might not be canon here. For example, I have no idea what happens before or after Dean turns into a Demon. So I apologize if my story tends to stray off of the canon world.
It had been 4 months since Dean disappeared. But the world has gone on. Castiel didn't quite understand. He wanted to scream out into the world: "Dean Winchester is gone. I don't know where he is. Why are you going on as if nothing happened?"
But of course no one was around to hear. Sam was in the library of the bunker trying to research for possible leads. Castiel sat helplessly at the large table. He was dressed in one of Dean's t-shirts, the ACDC one that Dean had given him a while ago, and a red hoodie. Despite that, he was shivering. It wasn't because he was cold. No, in fact he was quite warm. But that didn't stop the endless tremors going down his spine. Maybe it was the shock. Or maybe Castiel had gotten some terrible disease that made you shiver. It was quite possible now that he had lost his Grace.
The room was eerily silent. It was as if everything had been put on pause. But suddenly, there was a knock at the door. Castiel stood up. He couldn't think of who it could possibly be. It couldn't be Charlie. She had returned to Oz after a quick visit. And it surely wasn't Crowley. Crowley didn't know where this place was.
Castiel slowly walked to the entrance of the bunker. He looked through the small peephole. His eyes went wide. The whole world seemed to regain colour. He quickly called for Sam, who came running out of the library to see what was wrong.
The person on the other side of the door was Dean. Dean who had gone missing four months ago. Dean who Castiel had missed terribly. Dean who had said he loved Castiel. Dean who was standing, leaning against the wall outside of the bunker.
Castiel quickly pried open the door. He ran into Dean, arms wrapping around the familiar body. But something was off. Something was different.
And then Dean through Castiel off, with strength that couldn't have been human. Castiel lay on the ground, trying to figure out what had just happened. Sam just stood, not knowing what to do. Dean smirked at that. And then his eyes flashed black.
Sam reacted quickly, taking out his knife. Castiel was on the verge of tears.
"Sorry about that. But I'm here for business. Following direct orders." Dean said calmly. Much too calm for the situation.
"Whose orders? Crowley's? Is that what you're reduced to Dean? Following around Crowley like a little puppy?" This elicited a growl from Dean.
"I am Knight of Hell! How dare you speak of me in that way!" Dean lunged towards Sam, but Sam was too quick. He knew Dean's moves. After all, Sam spent his childhood admiring Dean. He grabbed his vial of holy water from his pocket and splashed it onto Dean, who hissed. In that moment of distraction, Sam grabbed the handcuffs with the Devil's trap etched into them, clicking them onto Dean's wrist. Dean swore, trying to break free. Sam dragged Dean down to the dungeon where they had once kept Crowley. Coming back up, He spotted Cas still on the floor.
Castiel didn't even begin to understand what had happened. He was in too much shock. There was a deep gash in his arm from when he hit the ground. But he didn't notice it. Sam helped Castiel up and lead him too Castiel's room where he tended to Castiel's wounds. He made some of Cas's favourite tea and told him to rest.
Sam returned to the library, but this time, he found all the books regarding Knights of Hell. He was sure there was something considering that Abaddon came to 2014 while trying to kill the Men of Letters. He finally found something. Quickly skimming through, he quirked his eyebrows at something that caught his attention. A Knight of Hell could be converted back into a human with a true love's kiss. But the Knight had to be completely free. That meant no Devil's traps. This was going to be difficult. But not impossible.
Sam quickly went to Castiel's room. Castiel was sleeping. His mug almost empty. Sam couldn't help but think of how vulnerable and broken Cas looked, without his grace and without Dean. Sam wasn't sure how all of this happened. One thing led to another.
It simply started off with the family business. A Wendigo here, a vampire there. But now, everything was complicated. Hell had broken loose. There were angels who happened to be absolute dicks. The brothers had died and resurrected countless times. A normal human would never even dream in their wildest dreams the things that always seemed to be happening to Sam and Dean, but here they were.
Sam walked to Castiel's bed, shaking him slightly. Castiel awoke instantly, though the exhaustion was still plain on his face. Sam explained what he had found out from the book. Castiel listened to every word, eyes going wide. And then he could feel the hot, burning prickle of a tear in his eye. What if he wasn't Dean's true love? After all, Dean has had multiple lovers in the past. None of which lasted very long, but Castiel had only been with Dean for a few months as well. But Sam reassured Castiel that the way Dean looked at him was unlike anyone else Dean had been with. Sam was positive that Castiel would be able to convince the demon side of Dean to realize the human feelings. So together they planned.
Sam would stay outside of the door of the dungeon with the knife and holy water in case things didn't work out. Castiel would go in, free Dean of the handcuffs, and disconnect the Devil's trap. He would try to convince Dean for that one kiss. The one kiss that would end all of this nonsense.
And so, Castiel opened the door to the dungeon, carefully closing it behind him after he entered. It was dark in the room, with only a single candle lit, the flame flickering, casting ghostly shadows on the walls. Dean sat quietly, smiling up at Castiel.
"So what brings the little angel down here?"
"I'm not an angel anymore, Dean. I lost my grace."
"Oh how unfortunate"
"Dean. I know the human part of you is still in there. Please. I know you're strong enough to break free of the demon. Please Dean. It's me. You told me you loved me just a few months ago. So please, if you can hear me, please fight the demon." And with that, Dean's eyes flickered back to the beautiful green it was before the transformation.
"Cas? What's happening?"
"Dean! Do you remember anything?"
"I… No. Not really"
"Crowley turned you into a demon. I somehow found your human self but the demon side may come back any moment now. We have to hurry. Sam found a book on Knights of Hell. A true love's kiss will free a soul from a demon."
"Well then what are you waiting for? Kiss me already, dammit."
And so Castiel carefully removed the handcuffs that had made Dean's wrists red. And he used a small knife to scratch at the paint of the Devil's trap. Dean stood up and hugged Castiel. As Castiel leaned into Dean, their lips barely touching, Dean's eyes flickered back. And Castiel felt the searing pain.
Castiel had managed to turn Dean back, but not quickly enough for Dean put a blade through him. Castiel fell to the ground. Dean, now human, realized the situation. Dean couldn't stop the tears. What had he done? He knew what was happening as the demon within him tricked Castiel. But he couldn't stop it. Dean felt to his knees, cradling Castiel's head.
"Cas. Oh Cas. I'm so sorry Cas. I couldn't stop it. I couldn't stop any of it. I'm so sorry. I love you. Oh god I love you. I'm sorry"
"I love you too Dean," Castiel wheezed out "Dean, could I ask you one last favour? Will you sing for me?"
"Anything for you Cas" And so Dean began rocking Castiel back and forth, singin Hey Jude, just as his mother had done so many years ago when he had been afraid of the dark. The tears kept coming., breaking up the words in the song. He hoped the song would never end. That Castiel wasn't dying. That he wasn't dying because of Dean. But the end was inevitable.
"I love you too Dean. And I forgive you" Cas smiled weakly. And with that, he let go of his final breath.
A/N: I'm so so so so sorry that I made this beautiful idea into this little thing. It's really late right now and I don't have a beta so there are probably 5000 plot holes but I hope you enjoyed anyways. So thank you for reading :)
