Contains spoilers for this episode and earlier episodes.
Nam-ra's strength helps the students fend off Gwi-nam while they struggle to reach the roof. Cheol-su tells the arriving soldiers that he is the only survivor, and the helicopter leaves with him before the others get through the door. Once outside, the classmates arrange an SOS signal in case another aircraft returns. Eun-ji's fire in the school offices triggers the sprinklers, while the students on the roof must settle into another period of waiting.
The group lights a fire with Nam-ra's lighter and begins speaking more openly about life before the outbreak. The fire gives them a chance to sit together without another immediate chase, although they are still stranded above the infected. Cheong-san finally tells On-jo that he has liked her since childhood. She is upset by the confession and steps away, unable to answer him as he hopes. Their friendship is suddenly another difficult subject they cannot put safely aside.
Below them, Na-yeon watches the farewell messages recorded on the camera and confronts her guilt over Gyeong-su. Remembering Sun-hwa's plea that she help the others, she packs food and drinks and leaves the storage room. Gwi-nam intercepts her and bites her neck before she can reach her classmates. Elsewhere, Ho-cheol returns with a vehicle to collect Jae-ik and their companions. On the school roof, Gwi-nam climbs back into view and attacks Cheong-san, trying to take his eye.