Sam ran down the hall, the demon blade clutched tightly in his hand. As he approached the doorway to Dean's room, knots and pin pricks started afflicting him in the pit of his stomach. He knew he wasn't going to like what he saw when he turned the corner, and as he got closer and closer he could make out words being spoken, whispered almost, but they weren't loud enough for them to have any meaning.
He reached the doorway and he braced himself before turning the corner, spinning the blade to hold it in an offensive position. He slowly absorbed the image of his brother, now rendered silent, pressed against the wall, his face an alarming blue color. Cas' hands were the ones holding him there, choking the life out of him. Dean's hands gripped the angel's tightly and Sam clung to the only sign that Dean was still alive. He wanted to do something; his body wouldn't obey his mind's sharp protests. Move, kill Cas, DO SOMETHING. What could he do? A demon blade wouldn't have any effect on the angel. He realized he could make an angel-banishing sigil, but instead of doing as his mind begged, the surprise and ridiculousness of the situation only allowed his mouth to simply open to utter one choked word: "Dean."
Stuck in his bodily prison, Sam could only watch, and his eyes found their way to Cas' face, the strain of his visible muscles, the blood collecting on his cheeks. His whole body was shaking in exertion, the knuckles of his hands were white as bone and he heard a few cracks as they re-positioned themselves on Dean's throat. Dean's hands, now that he was fully unconscious, slipped off of the angel's and dangled at his sides.
He couldn't understand what was happening, how Castiel could be doing this. To Dean. Sam's knees gave out, and he landed hard on them, the knife fell from his hands to clatter to the floor. He looked up at Cas again and this time his mouth conformed to his thoughts more completely. Sam began shouting. No words or phrases, just yelling, objecting Cas' actions in the only way he was capable. In amazement, he watched as one of Cas' hands retracted from its stronghold to move to Cas' chest. It was shaking violently, and Sam could hear a rolling, rumbling noise over his screaming.
He stopped yelling when the ripping sound began, and he was tempted to close his eyes, afraid of what was making the sound, afraid that Dean's body would be producing it. But he forced them to stay open, aimed at the catastrophe before him, vowing to watch Dean's last moments even if they horrified him.
As the ripping sound grew louder, Dean was bathed in a bright light, reflecting on him off of Cas.
"CLOSE YOUR EYES!" The angel commanded. He yelled it at the top of his lungs, yet it was still hard to make out over the sharp tearing sound. Sam wrenched his eyes shut, amazed that he was listening to the man who probably just killed his brother. Through his lids, the light intensified, as was obvious from the red glow that occupied his vision instead of blackness. The light got so bright that Sam had to push his hands over them as well. The disturbing sound kept growing louder as the light grew brighter until it cut off all at once, and Sam was thrown back against the hallway wall. His head cracked hard against the wood. He didn't wait for Cas to give him permission, his eyes shot open to see what had happened.
The trench-coated figure was crumpled on the floor, a scary, open wound in his chest. There was a frightening amount of blood surrounding the angel, yet Sam went straight to Dean, who had his back against the wall. A smile quickly took up Sam's face when he realized Dean's eyes were open, blinking rapidly. He gave his head a shake then looked up at Sam.
"Would you shut up a minute? Jesus," Dean said, wiping his hands over his face and scrunching his cheeks a little. Before Sam could respond, Dean noticed the body now still on the hard floor. He pushed Sam out of his way, Sam had to try and keep from falling over, and he watched Dean bend over the angel. His hands flitted helplessly over his body. "What the fuck happened, Sammy?" He searched Sam's face in a panic, his eyes wide and fearful. "What can I do?" He turned back to the angel, slid one hand under his neck and rested the other on Cas' cheek. Sam was in awe, he had no idea what had just occurred and how Cas received his wound. The only thing that could have hurt him was an angel blade and there wasn't exactly one lying around anywhere.
"Sammy! Shut up and help me!" Dean yelled, moving his hand from Cas' cheek to put pressure on the wound, staunching the blood flow. "God, don't let him die now. Don't let him fucking die."
"Dean, I'm not saying anything," Sam answered at last, a little worried about his brother's sanity. Despite his disapproval of the man who just tried to kill his brother, he stooped down next to Cas across from Dean to get a closer look as per Dean's wishes.
As Dean pressed his hand more firmly to Cas' chest as tears began rolling down his cheeks, they both went silent as they watched the blood surrounding the wound disappear, observed as the hole in Cas' chest vanished. Dean locked confused eyes with Sam for a split second before he heard a gasping breath come from the man in front of him, and they both snapped their heads to look at the angel now clutching his chest before them, his breathing heavy as he coughed hard.
Dean stood and moved behind Cas' head to push him into a sitting position, Cas leaning against his legs. "What the hell just happened, Cas?" Dean questioned once the angel's breathing had returned to a relatively normal rhythm. Cas took a long look at Sam before answering the Winchester behind him.
"I had to figure out a way to sever the connection between Naomi and myself. Guess it worked," Castiel smiled and chuckled to himself. "But more importantly," he began, pushing his head back to look Dean in the face, "how does it feel to be a celestial being?"