Nighttime arrived but Calter didn't sleep at all. He was just laying in his bed with his eyes closed but he was not really sleeping. Calter only did this so that Kence will not be worried about him
In fact, Kence doesn't have any plans on sleeping earlier. Only when he saw Calter 'sleeping' did Kence starts to sleep. After all, Calter helped him a lot before, and even in this mission, Calter is the main character, how can Kence not be worried about him?
There is also another reason why Calter wasn't able to sleep. His acute danger sense is warning him and Calter knew better than to ignore it. Soon, Calter found out that this decision of his is the correct one
In the middle of the dark night, a figure wearing a black robe on his whole body and a mask on his face can be seen sprinkling some green dust around that the wind carried away
The weird thing is that that figure was sprinkling the dust in the area around where Calter and Kence are currently staying