Contains spoilers for this episode and earlier episodes.
On-jo comforts Ji-min after the drone has revealed what happened to her parents. A noise through the broadcasting equipment suggests a way to reach Cheong-san: draw the zombies toward speakers while the classmates move through the corridors. Su-hyeok and On-jo tell him to wait for them, and the group leaves its refuge. A stray zombie disrupts the crossing, forcing Su-hyeok to stay behind while the others continue toward the music room.
Gwi-nam finds the route the students have drawn and confronts Su-hyeok, demanding Cheong-san's location. Nam-ra intervenes and is bitten before Su-hyeok sends the bully through a window. They rejoin their friends, but the wound turns the reunion into an argument about whether Nam-ra can stay. Cheong-san explains that Gwi-nam was already bitten in the library. Nam-ra struggles with the urge to bite Su-hyeok, yet does not change into an ordinary zombie or lose all control.
On-jo argues for trusting Nam-ra, while Su-hyeok ties himself to her to reassure the frightened classmates. They record messages for their families on a camera, including On-jo's tearful plea for her father to come. So-ju has found no schoolchildren among the evacuees and refuses to remain in quarantine. With U-sin's help, he escapes the guards and reaches the water under gunfire. In town, Jae-ik adds a little girl to the children he is trying to protect.