On late August 2021, an unexpected zombie outbreaks occurred in two simultaneous location: Hyosan High School and Hyosan Hospital. It all started when Lee Byeong-Chan sent the infected Hyeon-ju at the isolated room at night. When student Hyeon-ju bites the nurse, a mechanism started a massive zombified outbreaks that spread hundreds of students, as well as tens of thousands of residents of Hyosan. Now, the small remnants of high school students faced a difficult survivalism hardship on how to navigate the teamwork to fight against numerous zombies and leave Hyosan before the military bombed the small city.

Spoiler: Also, we placed Nam-ra travelled toward the military quarantine area rather than abandoned her friends. It would be complicated matters on determining the power of the military decision.