Martial law is imposed on the city. When Cheong-san is separated from the rest of the group, On-jo leads a mission to use a drone to locate him.

The group clears a path to Cheong-san using sound to draw away zombies, but a new type of threat surfaces. Nam So-ju breaks out of the quarantine camp.

A disturbance at the camp shifts the military’s understanding of the virus. A thunderstorm provides cover as the group agrees to keep on moving.

The students make it to the quarantine camp, each of them weighed down by tragic loss. Months later, they hang on to hope for a survivor.

When one of the group is scratched while fighting a zombie, Lee Na-yeon demands they kick him out. Outside, the virus swallows up the city.

In need of a cellphone, two students take a risky journey to the teachers’ office. Byeong-chan passes on critical information to Detective Song Jae-ik.

Inside Lee Byeong-chan’s science lab, a student incurs a seemingly harmless bite. Shortly after, a fast-spreading outbreak soaks the school in blood.

The infected multiply in droves. Scrambling for their lives, Nam On-jo and Lee Cheong-san find safety with others inside a classroom — but not for long.

The group clears a path to Cheong-san using sound to draw away zombies, but a new type of threat surfaces. Nam So-ju breaks out of the quarantine camp.

A disturbance at the camp shifts the military’s understanding of the virus. A thunderstorm provides cover as the group agrees to keep on moving.

The students make it to the quarantine camp, each of them weighed down by tragic loss. Months later, they hang on to hope for a survivor.

The infected multiply in droves. Scrambling for their lives, Nam On-jo and Lee Cheong-san find safety with others inside a classroom — but not for long.

When one of the group is scratched while fighting a zombie, Lee Na-yeon demands they kick him out. Outside, the virus swallows up the city.

In need of a cellphone, two students take a risky journey to the teachers’ office. Byeong-chan passes on critical information to Detective Song Jae-ik.

Martial law is imposed on the city. When Cheong-san is separated from the rest of the group, On-jo leads a mission to use a drone to locate him.

Inside Lee Byeong-chan’s science lab, a student incurs a seemingly harmless bite. Shortly after, a fast-spreading outbreak soaks the school in blood.