Air date: 2022-01-28

Runtime: 66 min

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.

Air date: 2022-01-28

Runtime: 70 min

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.

Air date: 2022-01-28

Runtime: 62 min

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.

Air date: 2022-01-28

Runtime: 72 min

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.

Air date: 2022-01-28

Runtime: 56 min

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.

Air date: 2022-01-28

Runtime: 67 min

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.

Air date: 2022-01-28

Runtime: 60 min

To make it out of the music room and onto the roof, the students put into action their most perilous plan yet. Elsewhere, Jae-ik comes across a setback.

Air date: 2022-01-28

Runtime: 58 min

Jae-ik and his crew run into a student from the school. Na-yeon works up the courage to face her peers. The group shares confessions around a fire.

Air date: 2022-01-28

Runtime: 61 min

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.

Air date: 2022-01-28

Runtime: 54 min

The auditorium quickly becomes a trap for the two newly united teams of survivors. Byeong-chan's video logs reveal a drastic solution to the crisis.

Air date: 2022-01-28

Runtime: 56 min

Though a surprise protector provides the group safe passage to their next stop, Yoon Gwi-nam is not far behind. The military makes a grave decision.

Air date: 2022-01-28

Runtime: 53 min

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.