Tower Sky, a luxurious building complex, has organised a lavish Christmas party for its VIP guests. However, things go awry when a fire breaks out and thousands of lives are endangered.
Yoo-lim, who divorced her husband and was preparing for a new start, learns that her daughter, Eun-ah, got raped by boys at school. However, they will not be punished because they are minors. Eun-ah kills herself, and Yoo-lim seeks revenge.
A class of students stays at school for a camp in an elite study group to finesse theirs and the school's grades. Upon the first night, the swimming coach is found murdered. As the students try to figure out what happens, a voice informs them that if they don't figure the murder out, students will begin dying in quick succession.
