Seeing as I had the means to continue, I began diving further.
The ice-cold spring water wasn’t a big deal, and I managed to at the 18th floor by the end of the day.
In the darkness of the underground lake, fish type monsters were swimming – such as the “Regular Backer Chub[4]” of around 60 centimeters that uses its thick lips to attach itself to one’s meat in order to weaken and remove it, and the “Super Characin[5]” of around 1 meter that attacks with its fangs and fins that are as sharp as the edge of a knife -- and even though I had to plunge into the deep gloom to approach them, I didn’t mind as they were very delicious.
Advancing in the gloomy subterranean lake was more mentally tiring than I thought.
It seems like if I would be untactful, my body would have been cut by protruding rocks.