"Hey, look, what's that?"

All the experts and instructors beamed happily when suddenly a student shouted out. His flashlight flashed across the students around them and suddenly stopped at the corner of the passage ahead. Unexpectedly, there was a small pile of yellow soil. There was a cave entrance nearby. It was in the shape of a square with a width of about 70 or 80 centimeters.

Everyone's eyes were focused on it.

"Rob-robber ...