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.

The episode was rated 7.78 from 413 votes.

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.

The episode was rated 7.77 from 391 votes.

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.

The episode was rated 7.76 from 449 votes.

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 episode was rated 7.74 from 445 votes.

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 episode was rated 7.73 from 414 votes.

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 episode was rated 7.70 from 402 votes.

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.

The episode was rated 7.68 from 406 votes.

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 episode was rated 7.65 from 529 votes.

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.

The episode was rated 7.56 from 418 votes.

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 episode was rated 7.31 from 648 votes.