A deadly virus outbreak hits Seonghyeon High School when a zombie liquid drops on a student in the science lab, and it spreads. Classmates begin to turn into violent, fast zombie creatures. Sohee was a quiet transfer student who always kept to herself. She had the highest grade in the class and didn't talk much. Meanwhile Jeongin was quite a popular student/heartthrob, but he had mediocre grades. Jeongin has had a crush on Sohee since middle school, but never told her. When the apocalypse broke out in the gym, Jeongin was the first to protect her and take her to a classroom where they find seven guys (Seungmin, Felix, Han, Hyunjin, Changbin, Minho, and Chan), and three girls (Ji-hye, Ha-yeong, Sung-mi). "If we don't make it out alive, I'm glad I met you." "School was hell, but now it's deadly."