It was like we just waltz right into a gloomier, grislier reality entirely separate from the one we just left. Even the air felt different. Fresh and invigorating on the outside, yet cold and musty on the in.
Unnervingly fascinating what a simple change of lightning can do to a place. The last time I found strolling between stale walls of concrete and crunching bits of debris at my feet, daylight was still bouncing from every gap and crevice, you could see from one end of the hall to the next, and nothing felt like it was trying to trip your balance all the way to a broken nose.
Take away the sun, get rid of any sense of spatial awareness, hearing nothing but your own breathing and footsteps echoing in a void of pitch-black, and now you start worrying about any ghouls and monsters that may or may not be lurking around the next corner.