Sam's voice trembled with fear as he tried to reach Dean through the metal grate.

"Dean? Dean, can you hear me?"

They were both curled up in some kind of concrete cell. It was too low to stand or even sit up and too short to lie down fully so Sam had his knees pulled his chest. His legs were starting to cramp up and he couldn't remember how long he had been down there with his arm outstretched trying to reach an unconscious Dean, who he could see the huddled silhouette of through the thick, rusty metal of something which resembled an old sewage grate.

Sam paused in his efforts to try and listen. He didn't know what for; he just tried to hear something - anything. As usual there was the slow drip of water with a distinct echo. There has to be a bigger room near us somewhere. That kind of echo didn't happen in a space the size of this, but Sam dreaded to think what was in that larger room.

A stench of damp was around all the time. Sam didn't know how else to think of the smell, it was just damp. The air felt heavy and every surface felt like it had a thick layer of grime. Sam's eyes had adjusted to the dark enough to be able to distinguish size and shapes but the lack of light left everything in various shades of dark grey. From experience, he imagined that the walls would be covered in thick, green sludge.

He had worked out long ago that they were underground somewhere, probably in an old abandoned sewer of some kind. Typical, why do we never get kidnapped by someone with class?

The current situation wasn't what had Sam shaken up, they'd faced far worse. No, what troubled him was what had happened beforehand.

Before he could follow that train of thought any further there was a low groan from his right.

"Dean!" he called out, relief flooding into him.

"Dude, what the fuck happened?" Dean's voice was raspy and he winced as he spoke.

"I dunno man, we're in some sort of sewer dungeon."

"Wonderful," he responded gruffly.

"It's crazy, I never thought she would turn on u—"

Sam's words were cut short as an invisible force wrapped around his throat like a rope being pulled behind him. His head was pulled back to the floor and his hands flew to his neck instinctively but there was nothing to pull away.

"Sam?" Dean sounded confused.

Sam struggled for breath but managed to make a vague noise which sounded like he'd tried swallowing a watermelon.

"SAM!" Dean yelled, as he finally saw what was happening.

Dean managed to roll over and thrust his hands through the metal bars but he did about as much good as Sam's own grappling.

There was suddenly a small crack of light where the wall met the floor. It was only dim, but to Sam's dark accustomed eyes it felt like staring into the midday sun. He tried to yelp but nothing happened as he was blinded by the beam of light. Feeling the floor shifting beneath him he wondered if the choking would begin to loosen.

Instead it tightened and an almighty pressure on his chest made a cracking sound as he felt at least two ribs break. There was a warm trickle from his mouth as he coughed and from Dean's distressed yelping he could only imagine it was blood.

"SAMMY!" Dean's voice was cracking and he was smashing into the grate with all the force he could muster.

Sam saw spots in front of his eyes. Dean was still yelling his name and pounding on the metal when, suddenly, the floor fell away beneath them and everything went black.