"Cas, you son a bitch."

Castiel turned around, and immediately regretted the decision. Dean was at the other side of the previously empty hall, rage flashing behind his emerald eyes. Despite his trouble understanding emotions, Cas couldn't mistake the downright anger and merciless the Winchester was showing. A shudder travelled down his spine, and his head bowed as Dean stepped towards him.

Castiel could feel his stomach drop as he saw a glimpse of the shining silver blade Dean had produced from his pocket. Castiel could see Dean move the blade around in his hand, before his grip tightened and it stood still, almost shining in the light.

Trembling, the Angel looked Dean in the eyes, as if to look for forgiveness. At this point Cas knew apologizing would be useless.

An uncomfortable silence continued and Castiel could feel himself getting weak at the knees.

Dean cleared his throat and Castiel stiffened at the gruff tones of his voice, the last voice he knew he would ever hear.

"Right, you can use your Angel mojo bullshit to get your ass outta here, but I'm still gonna kill you Cas."

"I'm sorry, Dean." Pleading was worthless, but it felt necessary.

"No, Cas, You're not." Dean's anger was obvious as the sentence turned into a shout. "What you did to Sam was out of order".

Castiel was silenced. He had no idea what to say. But he had come to a decision – Dean was right. Even though it was beyond his control, it had been him who had killed Sam. Not remembering it doesn't make him less of a criminal, he thought. Waking up on a cold floor next to a bleeding Sam had affected him, but not nearly as much as it had for Dean.

Using all the courage he had, Castiel mustered up the words that needed to be said.

"Do it".

Cas watched as Dean stepped forward and lunge the silver blade forward. Dark crimson blood spread across his dirty white shirt. He heard a hard inhale of breath, then felt Dean's arm turn.

Dean pulled the knife out triumphantly and a sharp pain shot through Castiel's vessel. Castiel fell to the ground. A choked sound came from his throat and thick tears were pouring from his eyes. He could see a bright light coming directly from fresh wound. Sweat was pouring out of his body and his head was pounding.

Fighting back the pain he looked up at Dean, who still had the Angel blade in his hand. A smile spread across Dean's face when he saw Cas's eyes staring at him and he walked closer to the nearly unconscious body.

A small, gruff laugh escaped Deans lips as he got closer to Castiel.

"You deserve this" He muttered, hatred and venom in his tone.

As Dean walked towards the exit, Castiel managed to choke out two last words.

"I know"