I've had this idea for a while, and I'll probably rewrite it at some point during my life because I'm not really happy with it but then again I never think I would have been able to let it live up to how I wanted it to be, I've just been getting impatient with the fact that I haven't written it yet. I don't own any of Supernatural, although the angel in reference in this story is my unicorn.

Fleeting. Human lives had always been so fleeting, and Castiel had always known this. It had never been a problem, it was God's will; the way they had been created, and their creation was meant to be flawless. Not that any of that meant that their time upon the earth was so, breathtakingly, fleeting. Castiel had accepted this without much more consideration once it had occurred to him all those years ago, it wasn't something he had even been able to contemplate being directly relevant to him. It had taken a bit of adjusting to when he'd been human himself, but even that experience had been fleeting.

The only time it had ever mattered was when he'd found himself getting far too, almost unnaturally, attached to two humans he'd stumbled across the paths of and oh had they achieved so much; not all good, and a lot of the terrible things due to Castiel himself, the Winchester brothers made mistakes too but something shrouding with their humanity had differed their circumstances in a way that did not excuse them but gave a strange purity to what tore at them. Castiel knew now why his father had wanted them to be loved above all else, in a way that made him wonder whether this had always been his intention; for angels to dwell with humans disfunctionally enough for it to be family.

The Winchester brothers had crept behind him and attacked with the knowledge that one day, following days that would make the angel's experience with them seem as brief as Castiel registered all his life times, they would be gone. And if any two deserved to live to a decaying old age more than most it was the Winchesters, and if any two were less likely or less hoping of this it was the Winchesters.

This was a grief that tempered inside Castiel, true form and vessel, more agonisingly than anything – even Leviathans - he had ever experienced before. In the first creeping phases of the fact that the Winchesters would die Castiel hadn't know what it had been, nor now did he understand how angels avoided emotions as strong and crushing as these. The Winchesters were dangerous people to love, another fact Castiel had noted before even he had become attached. He had seen them die before, died with them even, and nothing in heaven could equal such an honour as what their sacrifices stood for. But on levels Castiel had always been through those moments certain that they were not as final as they would one day be, both Sam and Dean having ways of meeting exceptions in what reality could hold atop itself without buckling under the weight of.

He wasn't entirely sure what angels were capable of, in terms of maximums in the little things that made up humanity and not the irrelevancy of their powers, the things that he could not envy the Winchester brothers for, but respected them for being capable of through a life like theirs and have as a dream for him, a dream for him when the baby in the trench coat finally decided to grow up; for some reason Castiel had the suspicion that that time would some how tie in with the incidents that he was so terrified of. He was certain though, that he would cry for his brothers, who were his brothers too. When that ancient fast food addict finally cut the call and neither remained on earth to save the other from where ever they would end up to lay their weary heads.