The basement smelled like must and mold. Dean had smelled worse. Though the place didn't smell like rotten eggs, which meant no demons.
Dean could hear Sam's footsteps above him. Dean was glad he found a flashlight, though his car full of hunting gear would be nice.
He wondered where his car was, and how Sam lost it. He thought about the old couple living there raising their daughter, who now had a family of her own. Mostly though he thought of Cas.
Cas the fallen angel. Cas who had saved Dean's life several times. Cas who through away everything for him. Cas. Castiel.
Dean snapped out of his thoughts when he heard the door shut. He ran back up the basement stairs and turned the knob. Locked.
"Dammit," Dean muttered, under his breath which was now visible. "Sam! Sammy! The fucking door is locked! Sam!"
Dean waited a minute. Nothing. Dean walked back down the stairs, looking for another way out.
Goosebumps covered Dean's arms. He realized that the temperature must have dropped twenty degrees. The cold air sent a chill up his spine. Fog filled the room, fast.
Soon Dean couldn't see where he was going, the fog was so thick.
'Help me,' A little girl's voice pleaded.
Dean spun around, flashlight in one hand and salt (that he grabbed from the kitchen earlier) in the other.
Dean was ready to yell, come and get me bitch! When the fog disappeared and Dean heard the basement door unlocked.
So we are dealing with a ghost. Gotta tell Sammy. He thought as he ran up the stairs and out of the basement.