Long ago, Jeju was thrown into confusion by an outbreak of lust demons. Wonjeong, fated to save the island by establishing the Barrier, secretly visits and forms a friendship with two boys, Van and Gungtan, who were raised solely to kill lust demons. Ten years later, Wonjeong returns to Taejangsa Temple after completing her training to establish the Barrier. However, as soon as she starts establishing the Barrier, Jongryeong tries to burn Van and Gungtan, and the Taejangsa Temple becomes a scene of carnage.

Gungtan remembers once again that Wonjeong had sealed him in the past and escapes without being able to harm Mi-ho. Captivated by fear and anger, Gungtan begins to plunge the world into darkness. Mi-ho starts to blame herself, believing that the tragedy will only end when she dies. Meanwhile, illusions of Gusunsae cause Tamra High School students to engage in mass suicide. Despite Johan's effort to try to save the students, it wasn't enough. However, with the help of Butler Jang, Van and Johan work together and save the students.