The first time he saw it, he woke up startled. There was fast movement that had woken him up. As he sat up on the motel bed, he saw Castiel striding toward the window and there it was. There was a light glow emanating from Cas' body and it flowed around him. The tendrils flowed over his form and and trailed behind him. When he stood still, the light ghosted over him, barely visible swirls tracing aimlessly. Dean couldn't look away. The light was eerie and beautiful. But, it was late and no matter how intense and riled up Cas looked, if he hadn't woken Dean, then it probably wasn't a big deal. In the morning, Dean woke up, groggy and rubbing at his eyes and couldn't decide if the blue light had been a dream or reality.
—
The hunter thought nothing of the odd sight that night, until a few weeks later, when he was driving through a light snow storm. The snow flared up behind the car in front of him, leaving thin fingers of snow to trace the ground like a lover. As Dean watched, mesmerized, by the dancing snow, the image of blue light wrapping around an angel flashed through his mind. He was suddenly sure that that light had been real, but he had never seen the light since. When Castiel popped into the passenger's seat later that day, Dean looked over at Cas and wondered where the blue light had gone. But, Cas just looked over at him and began talking business, plans for avoiding angels and finding Lucifer and saving Sam, and Dean moved on and forgot about the delicate movement of warm blue light surrounding Castiel.
—
The angels surprised them, the day that Dean finally saw the light again. They were hunting what had appeared to be a shifter, but Dean and Cas soon learned that it was a trap and they had walked right in. It was one of those days that Dean was reminded of what Cas said before they were friends: angels are warriors. Castiel had been, and still was, one of the best. Three angels had appeared and Cas had stopped all of them, cleanly ending their lives and only receiving one injury. Dean had fought too, but when the last angel's blade sliced over Cas arm, Dean only stared. He almost missed Cas' smooth movement as he spun and buried the blade that had just cut him inside the other angel's chest. There was blue light practically exploding from the cut. The light was bright, almost eliminating the dark stain of his vessel's blood. But, the light was there, that same blue as the misty light tracing over his angel's form all those weeks ago. Cas planted his hand over the wound, hiding the light and looking irritated. As the angel moved forward, all power and purpose and fury, Dean could see it again. Traces of blue swirling over Cas' vessel and trailing off behind him. He shook his head and started walking after Cas.
"What the hell! You bleed light now?"
Cas just turned to him and tilted his head with his brow all scrunched and mouth pinched in irritation.
"That is my grace, Dean. Those angels were trying to kill me."
"Yeah, I got that. You kicked their ass. But, your grace? Like the thing Anna ripped out to be human? Like that true form the size of the Chryslar Building?"
"Yes, Dean. What else could it possibly be? My vessel?"
As Cas got more annoyed the conversation, Dean could hear the sarcasm that the angel had learned since he had begun falling. But, more than that, Dean could see the grace more. The light that had been like the dusting of snow, was thicker now, like fog rolling in. It looked tangible and Dean couldn't resist reaching out to run his hand through it.
Cas stiffened as Dean's fingers brushed through the light. His wide eyes followed the movement of Dean's graceful fingers. Dean trailed his fingers through the light, like he would water. It was warm and tingly. It felt soft. But, it wasn't truly there, there was nothing to hold onto. As he moved his hand, he felt the tickle of feathers. Somehow, the sensation was comforting and disconcerting at the same time. Every movement of Dean's hand kicked up the wisps of light, swirling them again when they stilled. He pulled the light, creating a current, as he brought his hand to wear the light swirled the most. When the currents seemed to meet, Dean stopped. The light danced madly around Cas' chest, near his vessel's heart.
Castiel gasped and it startled Dean. When Dean looked up to Castiel's eyes, there was fear there, and need. The angel's tongue darted out and over his lips and he breathed hard, like the fight had just ended.
"Dean, do you see my grace?"
"That blue light that shows up sometimes? Yeah. Should I not?"
"How long have you been able to see it?"
"A few weeks maybe? Not all the time… Only when you get aggressive, when it moves over your body."
"But, you couldn't see my true form, when I pulled you from Hell… This is odd."
Again, Cas inhaled sharply and Dean was surprised, but when Cas looked down to where Dean's fingers had begun playing with the warm light around Cas' heart. Suddenly, Dean felt a bit uncomfortable. He blushed a little and looked down and began to back away.
"'M sorry…"
The words were mumbled and a bit stilted, but clearly the moment had gotten too touchy-feely for Dean's comfort level. The time had ended and the hunter and his angel left before any other angels could come hunting them.
—
Castiel had been gone for a few days, but that wasn't unusual and Dean didn't let it affect his schedule. He and Sam had chosen a cheap motel and had settled in for the investigation, but they could only do so much in a day and Dean needed his four hours.
As Dean dreamed, the snow dancing over the pavement began to increase, but it was warm and softly blue, rather than the cold white of a true snow storm. He continued driving, pushing the Impala through the increasing strange weather. The snow had grown thicker, heavier like fog, and as it increased, the brightness and blueness increased. The light was soft and warm and began surrounding the Impala. It felt like home and Dean pulled over to get out. As he stepped out of the car, the light looked like dark grey-blue feathers fell dancing through it. The light swirled around him, little eddies forming wherever it curled over his form. Somehow, the feathers seemed to wrap around him, enfolding him, protecting him. He sighed in relief and then breathed in the odd light-filled air. At first, it was scary and a bit suffocating. It felt like feathers and water filling his lungs. The light was fluid enough to just flow into his lungs, but it wasn't truly tangible. Once Dean accepted the odd sensation, it felt like absolute safety. The feeling of light and feathers filled him and he continued to breathe it in. When he began waking up, he knew that the security and comfort of this odd vision of Castiel's grace would end and he was saddened, but he was a hunter and the day called him to go out and save the world.
As he opened his eyes, Dean was confused that he could still feel the warmth of feathers and light and grace. It wrapped around him, despite the fact that he could see the usual tacky motel paper and feel the cheap bedding on top of him. He rubbed at his eyes, trying to move out of the dream, but when he began swinging his legs out of the bed, he saw Cas. The angel was sitting on the edge of his bed and looking down at Dean. The look in Castiel's eyes made Dean a bit confused; Cas looked protective and concerned and, maybe, even loving, none of the things that Dean needed or deserved, so he shook his head a bit and ignored it.
"You always stare at people while they sleep? It's a little creepy."
The angel looked confused and a bit hurt, as though Dean had just rejected him and it made Dean flinch. As he climbed out the other side of the bed, he mumbled a quiet thank you, just loud enough for Cas to hear, but not push it into a Hallmark moment.
As Dean turned around, pulling his jeans on, he could see the light ghosting over Cas' form, like the fingers of a lover, like Dean longed to do. And, when he followed the light swirling over Cas' back, he could see it expand, fainter as it got further from his vessel. The light traced the outline of those black wings, every feather barely visible with blue light, just as Dean had seen when he first saw Cas all that time ago.