no signs of monsters at night

"We are adventurers from the Guild, we came to solve the problem in this place" Ye Chen said to the man in front of him.

"Just the three of you, it's really useless, you should go back, this problem is more complicated than you can imagine" the man said to Ye Chen.

"What do you mean, explain it to me" Ye Chen asked, he needed an explanation, Ye Chen didn't understand what was happening.

"Just like you, the adventurers who came, all became monsters that attacked people at night" he said to Ye Chen.

"How could that happen?" Ye Chen asked, Ye Chen needed certainty, what happened, why did they become monsters.

"We also don't know about the problem, they investigated and just disappeared, at night we saw that they turned into monsters" said the villagers.

"So that's it" Ye Chen, Shen Xinyue and Lu Sansa thought, it seemed like they already knew what might have happened.