Eventually the gang make it down to the remnants of the school.
Gwi-nam wants to stop Cheong-san from telling the police that he killed the principal.
Like in one scene, where the bullied girl went inside the room to eat goldfish and saw the teacher.
Could these others be those who Gwi-Nam infected? The military reports that there were 60,000 casualties in the bombing of Hyosan, with 50,000 of those being infected people and 10,000 of those as asymptomatic or not infected.