Prologue.

How in the world had he ended up in here? He looked around, trying in vain to recognize the place that served as his prison but it was darker than anything he had seen before.

"Sam?" He called, trying desperately to undo the ropes that held him captive. "Sam!" Louder this time. His voice echoed through the walls, the way it does when a room is completely empty, the sound bouncing against the naked walls. Which was probably the case.

"Dean?" The voice was barely above a whisper, but it was all Dean needed. It wasn't Sam's.

"Who are you?" He stopped fighting his bindings for a second, focusing on his surroundings. He could see no movements, but it was probably due to the total darkness. He couldn't hear a thing, either. Not even the wind he could certainly feel against his face every now and then.

"Dean? Is that you?" This time, the voice was stronger. It took Dean a second to pair that voice with a face.

"Cas?"

"What is this place?"

"You are the angel, why don't you tell me? "

"Dean?"

"Cas? Can you hear me, buddy?"

"Dean! Are you there? Dean!" Dean did not need to see his friend's face to know, he could hear the pain in his voice.

"Cas! Can you hear me?" He was almost yelling now, the echo hurting his ears.

There was no answer.

Anxiety took over Dean's body, making him fight stronger than ever against his restrains.

"Cas!" He shouted, but no sound came out of his mouth. "Cas!" He tried again, louder. Still no sound came out.