Castiel stood very still, staring out into the void. He had been ruminating in silence for what felt like an eternity. Though, in fact, it had only been about 25 years. But it had been 25 year of peace and complete autonomy. For the first time in his very long existence, Castiel answered to nobody but himself.
Death suited him.
Sometimes, he took long strolls through the darkness, other times he was content to just stand. Every now and again, he would sit down for a few months.
The only disturbance to his quiet was a small nagging voice.
"I'm begging you to just let me sleep."
"You can go to sleep whenever you like," Castiel calmly told The Empty. "I won't disturb you. I won't even speak."
The Empty appeared before him, a rare occasion, as these days it was often too tired to take a physical form. It appeared to him as a young Claire Novak. In the past, The Empty took many shapes in attempt to taunt or torture Castiel. The shapes of his lost loved ones and those he had hurt. Meg. Kevin. Kelly. Mary. Jack. Sam.
Dean.
These attempts at torture never actually bothered Castiel in his eternally contented state. In fact, he was happy to see the faces of his friends for a few minutes.
After Cass had been there for 15 or so years, as The Empty began to grow weary, it started to take the shape of whomever could illicit the response from Cass that best suited its need. The Empty was no longer in control of its own domain.
"You know I can't sleep until you sleep." The Empty pleaded with Castiel.
"Why would I sleep and be subjected to my worst memories for an eternity when I can stay here and remember my best?" Cass retorted.
"I'm supposed to be in control here Castiel! You're holding me hostage in my own home." The Empty spat.
"You did this to yourself, Empty. You tried to Maleficent me and it blew up in your face."
"What? Who…? Who is Maleficent?"
Cass shook his head, remembering that most cosmic entities know nothing of pop culture. "It's from a movie. Don't worry about it."
The Empty rolled Claire's eyes and sighed.
"Empty, do you know what the difference is between me and the other beings you have cooped up in here?"
"You're an irritating dick and they're not."
Cass gave out a small chuckle. "I am aware that I can be irritating but no. What's different is that angels and demons don't die of old age. None of us go peacefully in our sleep like humans do. We only go if we're killed, which means that most of us die in fear. And fear, no matter how small the amount, makes you easy to control. But me? You decided to take me when I was happy. That was your mistake. I had no fear, only peace, and you're can't take that away from me. And that makes you mad."
The Empty groaned. "Castiel…"
Castiel turned away. "I'd like to be alone with my thoughts now."
In defeat, The Empty slunk back into oblivion. Castiel looked into the long dark.
Then he decided to take a walk.
The Empty thought that Castiel had spent far too much time with humans. It knew humans and detested them. Too noisy. Too unpredictable. Castiel was noisy and unpredictable. It understood celestial beings and how to mold and subjugate them. But Castiel was no longer a normal celestial being. In fact, The Empty saw him as something else entirely.
Then it had an idea.
Another decade passed on Castiel's walk. He had spent his time thinking about how much he missed the early 19th century. For a small time back then, his vessel was a kindly street urchin who, despite being entirely destitute, constantly put others above himself. It was the first time Castiel had experienced true empathy. He didn't like was he did in that vessel, those acts weren't very empathetic. But he liked the man.
Castiel tried not to think too much of the Winchesters these days. Especially Dean. It often made him feel sad. He felt so strongly towards Dean and the thought of going so long without his best friend, of never seeing him again, was the only regret Cass had about his death. He tried to only think of the good times, but those regrets always came back up.
While Cass was walking, The Empty was plotting. It was absolutely desperate to sleep after over a quarter of a century awake. It was the longest The Empty had been awake in several millennia. It nearly had its whole plan together, but it was missing one last piece. The most difficult piece to obtain, not just because of its rarity, but because of the people it would have to talk to in order to get it.
It really hated conversation.
The first being it need to speak with was Death. The current Death was a tall yet slight reaper, formerly named Ramón. Death was shocked to be called as The Empty hadn't disturbed the reapers in many years. Not after it swallowed Billie.
"What do you need Empty?" Death sighed.
"I need to make an appointment."
"Well, unfortunately for you, I'm not a secretary." he chided.
"It's important." The Empty emphasized. "You have contacts I'm lacking. As it seems, I'm rather unpopular with the others."
"What makes you think that I'm in any better shape with them?"
"You do more business with upstairs and downstairs than me."
"Fine." Death relented. "Who do you need me to talk to."
"I need you to get that irritating woman with the accent who's in charge of Hell at the moment to tell the child who thinks he's God that I need something from him."
"That 'child' is God and he's far more powerful than you or I. You may want to pay him more respect."
The Empty was dismissive. "Whatever. Can you do it or not?"
"Sure. But if I scratch your back, you need to scratch mine." Death purred.
"What kind of favor are you looking for?"
"You've got a reaper in here who I have a debt with. She got herself killed before she could settle up."
"Done." The Empty didn't care about one measly reaper. It would give Death a thousand dead reapers for this one item.
"What do you need from Jack and Rowena anyways?"
The Empty looked out into the distance, its eyes glazing over. "I need to sleep."
Death shrugged, completely uninterested in knowing more.
Not long after, Death returned with Rowena, current queen of Hell, and Jack, current God of everything else. Jack looked barely older that the last time they met decades earlier. The good old days before The Empty made the worst deal of its existence.
"I got your message." Jack said.
"Why is she here? I only need to meet with you." The Empty sneered in Rowena's direction.
"I'm here to make sure you don't try to scam anyone." Rowena retorted.
"That's rich coming from you." It spat.
Rowen glowered.
"Enough!" Jack commanded. The Empty noted how Jack had grown into his presence since their previous meeting. "Why are we here? And why did you have me bring this?" Jack produced a small vial from his pocket. A human soul.
The Empty sighed and resigned. "I need a favor."
"Why would I do you any favors?" Jack questioned coldly.
"Because, once upon a time, I did you a favor."
"And then you killed the only father I ever had!"
"And he's why we're all here!" The Empty exclaimed. "Listen, you child. This benefits you too. I needed a fresh soul, you're the only thing in the universe that could provide one. And I have a bargaining chip for that soul that gets us both what we want."
"What could you possibly do with a human soul?" Rowena interjected.
"It's none of your business." The Empty dismissed her.
"Answer her." Jack demanded.
The Empty paused for a moment. "Castiel." It relented.
Jack was taken aback. "What about Castiel?"
"He won't sleep. I need him to sleep or I need him out of my hair for good." The Empty said. "The soul is for him. You get to save him, I get my rest back, and he never comes here again. It's a win for everyone."
"You're not trying to pull one over on us?"
The Empty rolled its eyes. "What possible underlying motive would I have for trying to permanently eject an angel?"
Jack resigned himself. He was sure there could be a possible motive but he was willing to take that risk in order to get Castiel back. "Summon him."
Castiel found himself in front of an audience very suddenly. It was the largest gather he had seen in 35 years. "Jack!" He exclaimed upon seeing his adopted son. He grasped him tight in an ecstatic embrace. "What are you doing here?" Castiel beamed.
"He's here to help me get rid of you." The Empty interrupted.
Castiel's face fell. "I don't understand. Jack. What's going on?"
"Castiel." Rowena moved towards him. "The Empty wants to make a deal."
"But it needs your consent in order to do so." Jack added.
"What kind of deal?" Castiel was shaken and was trying his hardest not to let fear creep in.
Rowena softened and she grasped Cass's arm lightly. "We're here to take you home dear."
Cass felt conflicted. On the one hand, he had finally found his contentment in the Empty. He wasn't sure if there was anything left for him. But on the other side, seeing Jack made him realize how much he missed those he loved. Castiel couldn't let himself hope that he may actually be able to leave. He turned to Jack. He was so proud. Jack had grown into everything Cass knew he could be and more. He reached out to his son's face. "It's not possible. I made my deal. And I'm fine with that."
Jack clasped Castiel's hand. "Cass, I've been trying to find a way to get you out of here for years and now, it's just being handed to us! Trust me." Jack pleaded.
Castiel did trust Jack and could tell that he wasn't as naive as he had once been. Cass turned to the Empty. "What's the catch?"
The Empty's face twisted into a maniacal smirk. "The catch is that you can't come back."
Castiel was confused. "Even if I leave, I'll always end up back here. Not today. Not tomorrow. But when I die. I will always end up back here. And its cruel of you to tell me otherwise."
"What's cruel is the torture you've put me through for the last 35 years!" The Empty roared.
"Cass." Jack interrupted the exchange. He showed Cass the vial. "The Empty had me bring this."
"Is that a soul?"
In a sing song voice, The Empty exclaimed, "You're going to be human and never bother me again!"
Castiel ignored the Empty. "Jack, where did you get a soul?"
"Cass, I'm God."
He squinted his eyes towards Jack. "Since when?"
"Since I… uh... kind of absorbed Chuck and Amara? Which was not super long after you ended up here." Jack gave an awkward smile.
Castiel was just coming to the conclusion about just how much he had missed. He turned to Rowena. "Human?"
"Yes, dear." She smiled.
"And when I die, I go to Heaven?"
"Or Hell if you're wicked enough." She winked.
Castiel took a deep breath. "Okay."
The Empty sighed in relief. Its nightmare was finally over.
Jack handed Castiel the vial. Cass opened the top and, taking one last look at his friends, allowed the soul to enter his body.
Then it all went dark.