In a prep-class for year-end exams, a sadistic killer puts the students through mind-games in order to save each other.
Yujeong is suicidal, yet she reluctantly goes to prison for volunteer work. There, she meets a prisoner who is waiting for death penalty. The two quickly fall in love despite their differences, yet they do not have much time.
The Family stays by Agnes deathbed, encounters Simon who returns to the family in 16 years and gives him a cold treatment.