It is late enough that the muffled sounds of the city in the distance are beginning to wind down, and even the frogs and nightloving insects have found their silence in the surrounding forest. Castiel shuts the door to his car quietly, as though hesitant to make any noise at all, and opens the heavy steel door to the bunker with equal care - though there is no covering the solid thunk it makes as it closes.

"Cas? That you?"

"Yes," Castiel calls back in a low voice. He's surprised Dean is still awake.

Dean shuffles into the entryway, flannel pajama bottoms and socks and a gray tee shirt with the collar askew, suggesting that perhaps he hadn't been completely awake after all. "You said you'd be rolling in late tonight. Figured I'd wait up for you."

A tired half-smile tugs at the corner of Castiel's mouth. "You do this every time. You really don't have to."

"I know. I just - I like it." Dean looks slightly embarrassed, and coughs to cover it. "Did you find it?"

In response, Castiel reaches into his pocket, closing his fingers around the glass vial that feels at once warm and cool to the touch. It is probably a trick of the imagination, but the glass feels alive as he draws it from the pocket. The blue wisps inside the vial illuminate the dim entryway, swirling in lazily shifting patterns on the walls around them and casting dancing shadows across Dean's face. The simple beauty of it has never once failed to take Castiel's breath away, and the way Dean's eyes go soft hints that perhaps it has a similar effect on him.

"Do you know whose it is?" Dean asks after a few moments.

Castiel shakes his head as he rolls the vial between his fingers. The attached chain falls from his palm and dangles, swinging back and forth. "It doesn't feel familiar. It was in a Douglas Fir in the Cascade mountains - I'll have to do some iconography research on that kind of tree. That may give me a hint."

Dean nods. "How many does this make?"

Castiel doesn't even have to do the math. "One thousand, four hundred and thirty-nine." He swallows. "I think I'm coming to the end of the ones on this continent."

The beat of silence is more telling than Dean's sharp intake of breath. "And then what will you do?"

The glass has grown warmer in Castiel's fingers; the glow within intensifies. Castiel closes his hand around it and pockets it once more, using the motion as an excuse to not answer right away. "I don't know," he finally replies, and it is an honest answer - one that he contemplated so thoroughly on the lonesome drive back across the country that once he nearly ran out of fuel. "Begin narrowing down which children the angels might have become, I suppose. I should start watching for signs. I don't know when they'll start to show, but they'd be - what - five years old now?" Castiel shakes his head, a little amazed. "Linear time is both frustrating and incredible."

Dean doesn't seem to have a response to this. Castiel doesn't mind. They have built a life on the foundation of silent understanding between them. "Are you coming to bed?" he asks instead.

Castiel takes a deep breath and tries to ignore the downcast shadow that flits across Dean's face for the barest of an instant at what he knows Castiel will say. "I - I'd like to spend a little time downstairs first."

Dean nods, and Castiel can see that he understands Castiel will not be coming to bed before light begins to touch the eastern horizon. He reaches out to squeeze Castiel's shoulder and turns, padding down the hallway toward their bedroom, the shadows swallowing him before he gets to the door.

The stairs to the basement of the bunker creak under Castiel's feet, and the darkness and quiet as he descends becomes absolute. He welcomes the dark, wraps himself in it as though in a cloak, letting it envelop him as his eyes adjust to it by tiny measures. He knows each stair intimately, and as he turns a corner he is rewarded for his perseverance by a sight that would not be nearly so magnificent had he turned on the lights - the incandescent blue glow flooding around the edges of the door at the end of the corridor.

The lock on the door is perfunctory - the angel- and demon-proofing sigils do far more to protect the room than any physical bolt ever could - but it makes Castiel feel better to have a barrier to undo before pulling the door open. He blinks at first - it is always so bright in the beginning - but just as his eyes adjusted to the darkness of the corridor, they adjust to the gentle luminescence of his room.

It is no more than a closet, really; there is enough room for him to stand and just barely touch each wall with outstretched arms. He shuts the door behind him, still quiet, still loathe to mar the quiet of the night, and scans the walls of the closet.

One thousand, four hundred and thirty-eight softly glowing vials reflect in his eyes, his expression one of mingled longing and contentment. Each one has its place on the pegboard Dean had helped him install from floor to ceiling. Some are familiar in the way a snatch of music is familiar; they bear labels in Castiel's meticulous penmanship: Daniel, Seraphel, Elendriel, Marisel - over a hundred in all, and they make a ghost of a smile play at the corners of Castiel's eyes. The remainders of his garrison.

The rest are no less important for being foreign to him. They are still brothers and sisters - seraphs, angels, and cherubim alike - and each vial of Grace hangs on its hook, silently and patiently waiting for the day when Castiel will lead his brethren one by one to the room for their reunion. They are days that will be a long time coming, Castiel knows; he can not expect the amnesia to wear off for years yet. Perhaps not decades.

Perhaps not at all.

Castiel draws the vial from his pocket and hangs it upon one of the last empty hooks. It dims slightly as it loses contact with his skin and swings like a pendulum on its hook. Castiel watches as the swinging motion slows and then stops, and the vial becomes just like every other one on the wall - and yet each is as different as the microcosm of a raindrop, distinct and unique.

He is sliding down with his back against the door now, gazing up at the placid incandescent constellations surrounding him. He hugs his knees to his chest, not so much for the physical warmth as for the inner warmth it gives him, and lets his eyes slide out of focus and the vials become blue blurs.

He no longer has his Grace; he had given up on reclaiming it long ago. He is instead the instrument of Grace, wandering the earth in search of the Grace of others; a caretaker, against a time in the future that may never come to pass.

But if it does, he will be ready.

Fatigue stealing over him like a thick blanket, Castiel lowers his forehead to his arms, intending to rest his eyes only for a moment. The last thing he sees before sleep claims him is the soft blue glow through the frame of his lashes, and he smiles to himself.