Ling Chang Feng reminisces about his marriage to Tang Qian Yue. At that time, Tang Qian Yue doesn't have any Butterfly Mark on her body, and she is visibly anxious and confused. Why does the vanished Butterfly Mark reappear? Ling Chang Feng deduces that the night raider, based on various characteristics, is a Butterfly Slave who has been infected with the Butterfly Pest of the Yilan Tribe. Once someone becomes a Butterfly Slave, they lose all their mental faculties and become extraordinarily aggressive.