We've been walking for around a minute in and all light from the outside had all but faded away. Only the lights from our lanterns remained. As we dallied in entering the pseudo-dungeon and were practically the last team to do so, we didn't come across anyone during our descent.
Reina was taking point, Vera in the middle, and I held the rear. Vera was in charge of mapping our movements. To get enough light to see what she was mapping, she cast a simple methodical magic that basically created a lamp that lit up the surroundings with a soft glow.
As we had the whole afternoon to reach the checkpoint and return to the surface, there really was no need to rush. If I had to guess the criteria for scoring, it most likely had something to do with the time we took.