In the beginning, Castiel tried to think of his punishment as a second chance. He had expected death. He had expected torture. He had expected hell. Heck, probably all three. But as the light faded and he was left standing by his lonesome, he wasn't expecting this.
He'd become human. No longer could he call upon the powers of heaven. No longer was he connected to the grace of his brothers and sisters. There was nothing except for the beating of his heart.
It seemed only Sam Winchester who came to understand the dire consequences of Castiel's humanity. After all, Castiel had no family, no background, no last name to fall upon. Even if Castiel was to assume the identity of Jimmy Novak, he seriously doubted Jimmy's family would ever accept him, let alone give him the necessary papers to do so. No birth certificate, no high school or college diploma, no money.
Dean had merely laughed at Castiel's insecurities. "Neither do we," the man had told the former angel. "It's easy to get an identity, Cas. Don't worry. You'll be fine."
And for a while, Castiel thought he was going to be. He had Dean, Sam, and Bobby. They were his friends, his allies. And he knew they weren't going to abandon him.
It wasn't until a month later, did Castiel figured out the whole scope of his punishment.
It was his first hunt. "Something easy," Sam had said. "Ghost. Salt and burn."
Not a ghost, they realized a second too late. A poltergeist and it felt the need to throw Castiel through a fourth story window. The height, the speed of which he fell should've killed him. Should've paralyzed him. But as Sam ran outside to check upon him, Castiel stood up without a drop of blood on him.
They tried everything. They cut him, they stabbed him, they burned him. Castiel even went so far to shoot himself with the Colt and it didn't leave so much as a dent on him.
"I don't understand," Dean said. "You're immortal. Okay, what does that mean?"
He didn't know. This was the wish of many humans and Castiel didn't have to kill anybody to achieve it. Why call it a punishment when it was sought by so many?
Once again, Dean tried to think of it as a good thing. They continued on hunts and Castiel took the advantage of being immortal to walk into dangerous situations first. Over the course of the next few years, Castiel would come to save many people. Come to be very good friends with the Winchesters. He made friends with others, made allies, even had sex for the very first time with a pretty brown haired woman named Maureen.
Then Bobby Singer died. Stroke. It wasn't until after the funeral, when they were burning Bobby's body did Castiel realize something.
Grief stricken silence reigned over the small group as they watched the flames engulfed Bobby's body. Castiel had experienced grief before but not one at this level. He was heartbroken that he'd lost the only home he'd ever known, but that pain was overshadowed by the new experiences of being human. This was different. This grief went deeper. It hurt more.
"Hey, Cas," Dean whispered. Castiel turned his head towards him and was startled to see tears in his eyes. "Bobby gets to go to heaven, right?"
Honestly, Castiel didn't know. He didn't know how humans were judged and who were allowed into heaven. "Yes," he said anyways. "Of course he does."
Dean nodded. Sam looked at him with weary eyes, because they both know the truth. But neither of them corrects it.
It was there, on that night, did Castiel realize his true punishment. In the obscure light coming off the flames, he began to notice the hidden scars on Sam's face. The laugh lines around Dean's eyes. He noted and saw and compared their looks to the very first time he saw them. It was subtle, but it was enough. They've aged.
And Castiel didn't.
This became more apparent when a year later, Sam fell in love. Claire was bright, beautiful, and they were married immediately right after she announced she was pregnant.
For the next few years Castiel would be known as 'Uncle Cas.' But as the kids grew older and Castiel did not, he kept his distance. At this point he'd become human enough to understand his immortality would only confuse and frighten his nieces and nephews.
Dean continued hunting. To this, Castiel was grateful. He was ashamed because it was such a selfish wish, knowing full well that he should've encouraged Dean to marry and have kids. Dean merely said to him, smiling, "Was born a hunter. I'll die a hunter."
Dean Winchester died at the age fifty-four. Diabetes. Sam had laughed bitterly at the irony of it all. "Of all things…" he chuckled sadly.
They burned his body. This time around, Castiel didn't need the flames to help him see the wrinkles appearing on Sam's face, the grey appearing in his hair.
With the death of Dean, Castiel felt as if a hole appeared in his heart. His friend, his best friend was gone. He was the human he'd gone to hell for, the one he rebelled against heaven for. And even with all knowledge he had of heaven, he had no idea if Dean was granted redemption. If he was in heaven or in hell.
Years would pass. Castiel kept in contact with Sam Winchester but kept his distance. He didn't want to see how old the man had gotten. How close he was to death.
It was at the age of seventy-three was when Sam sought him out. It nearly killed Castiel to see Sam hobbling over, leaning heavily on a cane. To notice cataracts in the hunter's eyes and arthritis in his hands. Despite this, Castiel hugged his friend for the first time in years.
Sam nodded. "I am," he said, though not sounding at all scared. "I'll be dead in perhaps a month."
"I don't want you to go."
It was another selfish wish, because Castiel knew he should be grieving the loss of Sam. Instead, he was scared to lose Sam because he didn't want to be left alone.
Sam had placed a withered hand on the former angel's shoulder and said, "It'll be okay, Cas. You'll be okay. Dean will not leave you down here by yourself."
Castiel shook his head. "Dean cannot help me with this."
"Idjit," Sam had said, right before slapping him across the head. "Don't underestimate my older brother. He's doing something. Trust me."
Though Castiel was the one who was thousands of years old, with the knowledge of heaven, he was in awe by the simplicity of Sam's words. This was the man who helped start and stop the apocalypse. This was the man who told him, with complete confidence, that Dean was going to help him.
Sam Winchester died two weeks later. Castiel attended Sam's funeral, grateful to see the amount of people who were there. He sat in the back, listening silently to the many people who talked about Sam and of Dean with fond memories. It was times like this, Castiel sobbed, that he was deeply grateful he'd turned his back heaven. Moments like these were worth preserving.
Castiel turned his head and immediately recognized his niece, Diana. She was in her late forties now, grey hair already staining her brown. Her eyes had grown wide at the sight of him, her head shaking in denial. "I'm sorry," she said. "I… I thought you were someone else."
That was the last time Castiel made any contact with the Winchester family. He stayed close, just in case a demon or some other supernatural being wanted to harm them. And for years, he made damn sure nothing did.
Sam's children had children. Then they had children. And they had children. Castiel tried his hardest, he did, but it was impossible for him to keep track of the Winchester's descendents. There were just too many. When he finally decided to leave his far-distance family alone, it was the year 2223.
Humans are irrational, cruel, frail beings. Castiel had agreed with Uriel on this, but he also knew there was a reason they lasted for so long. Human beings are smart. They are invented. They evolve. By the time Castiel left the Winchesters, colonies were already formed on Mars.
Castiel only took a wife just once. A beautiful black woman named Ophelia Woods. The marriage did not end well because she wanted children and he didn't. He did not think he could handle seeing the deaths of his own children- or worse, passing the curse of immortality onto them. That was something he would not risk.
More and more years would pass. Castiel would live to see the birth of the first clone human being.
He lived to see the nations of the world declaring everlasting peace, uniting under one rule.
He lived to see humans harvesting the power of the nova.
He lived to see the colonies on Mars move to Jupiter. Then Pluto. Then beyond.
By now, Castiel had lost track of the years. He did what he did best and hunted down supernatural beings. But at this point humanity had forgotten who Jesus Christ was. What the United States was. And as more and more humans left the Earth for the stars, with nothing to fuel their hunger, vampires became extinct. Werewolves became nonexistent. Ghosts merely faded away.
This confused Castiel to no end. Even as an angel, he'd never bothered to look beyond the planet his Father made. He didn't have to. Now that the humans had moved on, did that mean God's will only existed on Earth? Did that mean on other planets, in other galaxies, were there other creatures of unnatural abilities like God?
He thought about leaving Earth more than once. He never will, though. Despite what he thought or suspected, this was his home. It was here, he supposed, he will want to fade away into.
Or so he thought.
Castiel hadn't seen or heard another person in nearly ten years. It boggled his mind how he never gave into insanity, despite he had a very good cause for it. But he supposed he did at some point, because the person standing in front of him couldn't be…
Dean Winchester. The man, the face, the name Castiel hadn't thought of in centuries…
Dean cocked his head at him, frowning. "Dude, are you naked?"
He was. Castiel hadn't needed clothing in nearly forty years. The former angel gave out some sort of nervous giggle and thought hysterically, Oh God, I've finally snapped. And it only took three millennia to do it…
Castiel pointed at him. "You're…" his voice was rough from lack of use. "You're a hallucination. You're not here."
Dean took a step forward and Castiel took a step back. "You don't have to be afraid, Cas," Dean said to him. "It's okay. I'm real."
"I'm not, am I?"
Dean smiled and lifted his hand. Castiel nearly flinched away as Dean touched his shoulder. Warm, firm. "You're real."
Dean stepped back and Castiel gasped. No longer were they out in the wilderness open. Now they were standing in a motel room – a cheap one at that- and Castiel was shocked to feel clothing on his skin again.
And it wasn't any clothing. It was the familiar suit and coat he had worn when he was angel. He'd never thought he missed it, but he did. He looked up to Dean who was leaning against the bathroom doorframe, grinning at him.
It was suddenly too much for him. Castiel felt his knees buckle underneath him and Dean had to rush forward to catch him. The moment Dean touched him, Castiel burst into tears.
For years Castiel kept the emotion of loneliness at bay. It was there, on the edge of his conscious. He dared not touch upon it or he feared he would try to kill himself over and over, and with each fail, go mad. But now as Dean held him, the weight of the three thousand years fell upon him.
"I'm so sorry, Cas," Dean said to him. "I'm so sorry it took so long."
"I don't understand," he sobbed. "Why now, why here? Why…?"
"Zachariah," Dean sneered. "That little bitch kept me away this whole time. Believe me, Cas," he held Castiel's face in his hands, staring straight into his eyes. Green. Castiel thought. His eyes were green. "I've been fighting to get down here this whole time."
Zachariah. Another name and face he did not think of for even longer. He didn't care to. "If Zachariah wasn't allowing you…then who… ?"
Dean grinned madly. "I went to the big boss."
Castiel's eyes went wide.
"Sam helped. And we all agree it's time for you to come home."
Castiel was very close to hyperventilating. He was delirious with happiness, yet still stained with fear that this, all of this was just a hallucination brought on by delirium. "It's been so long," he said. "I don't know… can I…?"
"Of course you can," Dean said, helping him to his feet. "And if you can't, then I'm staying here right with you."
Dean began to glow white, light engulfing the hotel room. Castiel half-feared when the light dimmed, he wound find himself alone, again, in a world the humans left long ago.
So he grabbed onto Dean, held him tight.
And he went home.
A/N: Wrote this in one day, no beta read, so it's messy and weird and quite rushed. I've always liked fics like these, but hated the way how sad they ended. Either the character goes mad or simply endures till the end of time. So here, at least you kinda get a happy ending. Hmmm…