Charlie slowly opened the side entrance door and walked inside. It was dark, but fortunately it was still light enough to see, thanks to the emergency lighting. He found it interesting that while there were no people or vehicles around, there was still electricity.
He walked through the corridors of the building for a long time before he figured that it was just a wild goose chase. Perhaps he imagined what he heard? Maybe the weirdness of this situation was getting to him more than he thought.
Giving up his search, he walked back outside into the alley.
And that was when ...