Seul-gi, who became the top student in the entire school along with Jae-yi, is suddenly threatened by Byeong-jin and is worried that drugs will be detected during the health checkup. Seul-gi approaches Jae-yi, who calls her up to the rooftop.

Jae-yi, who learned the whole story of the incident, encounters an unexpected person in the printing room. Meanwhile, Seul-gi, who was stabbed, is taken to the hospital by Tae-jun, where she witnesses Tae-jun's eerie secret.