But no one expected that although the twelve children indeed entered the mountain together, an accident occurred on their way in...
When Mo Yan followed Xue tuanzi's guidance to the location where the twelve children disappeared, it was only through the subtle clues left on the ground that she was able to understand through her abilities that the children had encountered a group of extremely ferocious people here.
These people were all armed with knives and swords, and for some unknown reason, they tied up the twelve frightened crying children and took them deep into the mountain.
Based on Xue tuanzi's description, Mo Yan guessed that the group was probably preparing to descend the mountain to rob—it would explain the weapons. They must have caught the children by accident and, worried that the children would spoil their "good deed," decided to tie them up. Perhaps they are even now considering selling the children to human traffickers to make a fortune.