An angel's senses are far greater than anything a human could imagine. While standing in a bedroom, attention completely focused on something else, an angel would still be able to tell the color of fur the cat sunbathing on an old junker had, how many times the cricket on the fencepost outside chirped, and how hard the wind was blowing.
It was thanks to these heightened senses that the angel Castiel knew that with a final, resounding scream from Dean Winchester, a wave of grace exploded outwards, invisible to humans but scaring the cat from its perch.
His attention had been completely focused on her and following Mary's instructions to guide their child into the world safely, but he still noticed the expired butterfly on the windowsill flap its wings once, twice, experimentally before taking flight.
He paid no mind to the happenings outside of Bobby Singer's home as he passed their newborn daughter to her mother, wrapped in a fresh blanket. The rest of the world was not his concern as he brushed a lock of hair from her damp forehead, returning her wobbly smile with an uncharacteristic wide grin.
He dutifully ignored the fact that they still hadn't found the reason for the emptiness left behind by the now missing grace.
Dean stared down at her daughter with tears in her eyes. "Oh, Cas," she whispered, leaning against his chest, "What have we done?"
Mary, Sam, and Bobby had left them alone for the moment, giving the new parents a moment of peace with the new addition to their little family. The angel had wasted no time sitting on the bed next to them and kissing Dean gently the moment the door swung shut.
Cas chuckled softly and Dean felt something brush against her shoulder. She glanced up and realized that they were nearly engulfed by two huge, black wings. They were mesmerizing, dark as midnight and a bit scarred from his trek into hell to save her. She reached out a hand slowly, glancing back to make sure he didn't mind. The angel nodded and lowered a wing so that it brushed against her fingers. Gasping softly, she trailed her hand along the feathers, marveling at how soft they felt.
They sat like that for a while, wrapped in the warmth and comfort of the angel's wings, until they heard a knock on their bedroom door.
"Dean, Cas," Sam called from the other side. "Can I come in?"
Cas shifted slightly, his wings no longer visible, and Dean bit back a smile. They were something only meant for her to see. Not that Sam could see them anyway.
"What do you want, Sammy?" Dean scowled, her voice edging towards a whine.
"There's… something Cas should see."
The angel Inias sat on his knees in the middle of an abandoned park turned battlefield. The wind picked up, ruffling his hair and moving the swings just enough to produce an ominous creak.
"Forgive me brother," the angel before him smirked.
"Puriel," Inias sighed heavily.
"I must ask, why?"
"Why what?"
"Why fight? What could you possibly gain from all of this? Besides your death and the murder of our brothers and sisters?"
"Free will"
"You all keep saying that…" Puriel growled, "Do you even know what that means?"
"It means we would have the chance to discover what it means…"