As Lothur passed through the entrance to the cave that the winged beast had warned him about earlier, he came upon a large tunnel that led underground.
This tunnel had no artificial lighting, and what little lighting there came from the cave opening through which Lothur had entered.
However, due to the length and depth of this large corridor he was walking down, the place was getting darker and darker as he walked down there.
Luckily, Lothur had a phenomenal visual ability, able to ignore the visibility problem.
He might not see anything normal in the dark. Still, by observing the spiritual fluctuations in things in his surroundings, he could distinguish living beings from inanimate ones.
Because of this, Lothur was moving quickly toward the end of that tunnel, where he could already see some kind of construction different from what one would expect to find inside a cave.