Cas had always felt out of place. On the outside looking in. In a way he never belonged in Heaven amongst the angels, his so called brother and sister. He certainly did not belong amongst the humans. It had been this way for centuries, excluded for having free will, while ironically having no choices.
In truth there had only ever been one place he felt wanted, with the Winchesters. They were unwanted and mistreated by the world just as Cas had been. Only they truly understood Cas. 'Team Free Will' wasn't much but they were family.
Family, an odd occurrence Cas had been seeing for centuries, but never understood. Never understood why humans chose to from connection knowing that a moment of content could bring a lifetime, sometimes longer, of misery.
It was only when Cas was accepted into a family that he understood. Family, they are there for you through the good and bad times, especially the bad times. His family, Sam and Dean, had saved each other and him on many occasions. Literally damming themselves to Hell in order to bring salvation to the other.
That was in part the reason he had searched for Claire, so that he could make up for his past mistakes by inviting her to join 'Team Free Will.' To give her a family that could protect her and always be loyal to her.
Cas felt a great sadness when he watched Claire leave. He felt as though he was loosing everything at once.
Once again he felt astray. He lost Claire and he was about to lose Dean. He had this sickening feeling that this time there would be no coming back, no cure, no resurrection. He knew that if Dean left he would never see him again.
"How are you, Dean?" He asked trying to mask his emotions.
Dean turned towards him and gave a sad smile, "I'm fine."
Cas took a moment to answer as he tried to read Dean's true feelings. "No, you are not."
"I don't know man, everyone keeps asking. But I don't know. It's not that I'm afraid of dying, I mean I do that on a regular basis, I…I am scared of what I might to turn into again. I'll fight to the end, go down swinging…it's…it's just sometimes I am not sure what I am fighting…"
"Don't say that…how did you put it last time… screw destiny, we stopped the apocalypse, stopped the Devil and the Leviathan. We are cable of fixing this or we will die trying."
Dean gave half a smile, "Maybe I'll see you in Heaven then."
Cas frowned, surely Dean must have realized that even if he managed to die without the mark, the King of Hell would make sure that he never reached Heaven. "I don't thi…" Cas saw Dean's expression change, he realized he should rather lie. "Of course you will."
Dean gave a sad chuckle, "If you're going to survive on earth you really should learn to be a better liar."
They stood in silence for a few moments until Dean said, "Listen, I don't know what will happen but I know that I don't have a future. But you should know…I want you to know, that if I had one I would want you to be part of it."
Cas felt hot tears on his face, "Why does this conversation sound like a goodbye."
Dean gave a small shrug, "Probably because you don't know anything about social cues. I am not saying goodbye, if I was saying goodbye it would be much sappier and I would probably say something about you and Sammy sticking together. Sammy would definitely be having a chick flick moment."
Cas couldn't stop the tears. He closed his eyes and prayed to God, to the Archangels, to anyone that was willing to listen, to save Dean. He was brought back to reality by Dean's fingers brushing gently over his arm.
With that gesture Dean left the room.
Over the course of the next week or so Dean acted strange, as if he accepted his destiny. Sam and Cas only later found out what that meant.
According to the note Dean left, he accepted that he couldn't fight anymore and that he couldn't every die. According to the note, immortality was the only option.
That is why Dean had summoned Death and begged, for the first time in his life, for help. Help not for himself but for his family. Begged for Death to lock him away in Purgatory for the rest of eternity, which he must have done as Cas could not find Dean on Earth, in Heaven or in Hell.
As Sam and Cas searched for a way into Purgatory, Cas smiled to himself and thought, "You were right Dean, we will meet in Heaven, no matter where that might be." For Cas knew that any place, even perdition would be his paradise as long as he was there with his family, with Dean.