The year was 2020. Castiel stands over two gravestones, hands in his trenchcoat. His lips part, buts shuts just as quickly losing his train of thought. He knew this day would come, but he always thought they would come back. But that was the last time.
He remembered everything clearly. It was the Winchester boys and himself. It was always him and the Winchesters. Team Free Will always thought they would walk the Earth. Almost everyone thought that. The first one to see the end was Sam. His death happened faster then a man could take a bullet. The blood was escaping from his mouth, and slowly dripping down to meet the floor. Dean lied next to him holding his slowly becoming limp body. Castiel sat next to Dean, unsure of what to do. The angels still weren't back yet, so Castiel had none of the angelic powers that could have saved the day.
Days, weeks, months past, and both Castiel and Dean were still counting pennies waiting for Sam to come back. In between hunts, they would ask other hunters, 'Have you seen Sam Winchester?' But they would always get the same response, 'who? Oh um no,' 'he's been dead for a while now,' 'he'll never come back.'
Some nights, Castiel would hold Dean in his arms, as Dean would cry for seconds, minutes, or hours. They both wondered when Sam would come back and why hasn't he resurfaced. The world still needed him, they still needed him. Without Sam, where was the super genius, who dropped out of college to help Dean find their dad?

-
2 years past, and Dean aged some, Castiel looked the same. They both would look at each other every now and then, and give each other a faint smile or even a laugh. People think they're old couples, but they may even be right. But they may even be wrong, they kept a lot of things to themselves since Sam passed. They always thought it would be best.
The last hunt they went on together, would be the last anyone would see Dean alive. The blood spilled all over the place. They didn't expect it to end like this, even though they did. Dean's body lied on the cold ground and Castiel cried on Dean's leather jacket, asking where has the world gone. His mind was scattered, as he screamed Sam's name asking for help, unknown on what to do. His mind was lost, along with his words and everything else in between. He never knew why he screamed Sam's name when Dean died. He already knew Sam wasn't listening.
2 days later, and both brothers were next to each other, buried 6 feet under. When Dean was still alive and kicking, he and Castiel couldn't bare to burn Sam's body even though it would have been better. Now, Castiel couldn't burn the boys. It was far to hard on him, and they were his friends. The only true ones that he'd know. He stared at the newly removed put back soil and turned away, running his hands through his hair.
A year passes, also known as 2020, present time, and Castiel has tried everything to be with the boys again. But he can't. His once angel self forces him to live on, and not die. He continues to hunt alone and being a sad fallen angel. He's tired and wants out, but he knows he can't. He's been to the graves so many times he stopped counting, but he knows it's in the low 100's.

Half a year passes passes and he meets with an old friend of his, a fallen angel. But the fallen angel does not remember him, for it is just a vessel. Castiel carries on, walking alone in the street working on the case. He wonders why he can't have friends anymore. He doesn't like being alone.
New Years eve comes, and Castiel is sitting alone on a couch. He's a sad and alone fallen angel, asking where the Winchesters are to some unknown force. The tv's on, but on a low quiet setting. It's broadcasting live on New York City. He paused his small chat to the unknown forces and yelled for Sam and Dean, almost to tell to them the ball is about to drop, but remembering they are not there anymore.
The TV starts screaming down from 10 seconds, as Castiel takes a beer in his hands and a few sips. He remembers working on a Case back in Texas, and a little girl telling him to make a wish when New Years day comes. 3 Seconds until the New Year. He starts to think on the wish with the beer now set upon the table, and his face in his hands.
The year is now 2021, fresh snow blankets the ground, and Castiel steps forward, making imprints behind him. It's been 17 days since January 1st. Castiel finds a tree and slides down it to sit on the ground. He feels a long-awaited peace over him. He slowly shuts his eyes as he parts his lips for the last time. His wish came true.
"Til Death Due Us Part."