All of Us Are Dead

About the series

Contains story spoilers.

A violent outbreak begins at Hyosan High after science teacher Lee Byeong-chan’s attempt to make his bullied son stronger produces a virus that changes its host instead. The chain reaches the school through a student bitten in Byeong-chan’s laboratory; panic then moves faster than explanations. In the corridors, familiar classmates become attackers, and the school’s ordinary divisions suddenly matter in new ways: students who know one another’s habits must decide who can be trusted while looking for a route out. The season keeps the origin close to the students’ crisis. Byeong-chan’s motive is personal, but the consequences spread from his family to a whole town, turning a parent’s desperate intervention into the outbreak’s first cause.

Nam On-jo and Lee Cheong-san try to gather classmates into a classroom as the infected overrun the building. Their friendship predates the outbreak, and Cheong-san’s feelings for On-jo add a private tension to decisions that have to be made in seconds. Lee Su-hyeok, who has a reputation as a former troublemaker, becomes one of the group’s most capable defenders. They push desks and other furniture against doors, look for phones and watch for movement beyond the windows. Each temporary shelter buys time, not safety. The students have to cross halls where noise draws the infected, and they cannot count on adults reaching them quickly. Their small plans—signal, barricade, move together—become the only practical way to make progress.

Fear also turns the group against itself. When classmate Gyeong-su is scratched during a struggle with an infected person, Lee Na-yeon insists that he be isolated, while others argue over whether the wound means he will turn. The dispute is sharpened by the class prejudice and contempt that existed before the crisis. Na-yeon secretly contaminates Gyeong-su’s injury with infected blood, making the danger real and destroying the group’s trust in her. Gyeong-su leaves rather than force his friends to keep him inside; Cheong-san whistles a tune they share, distracting his infected friend, who dives out of the window. Their teacher, Park Sun-hwa, leaves the room to search for Na-yeon, and the students lose another adult who had been trying to hold them together.

The outbreak also produces people who are bitten but do not lose all awareness. After Gwi-nam is attacked, the infected stop treating him like prey; he stays conscious and keeps chasing Cheong-san. Byeong-chan’s recorded explanation describes a virus that can adapt around human consciousness. In the next stage, Nam-ra admits that Gwi-nam bit her. She feels a sudden urge to bite Su-hyeok, but does not turn into the same kind of attacker as classmates who lose control. Su-hyeok stays beside her while the others argue over what to do. Nam-ra’s hearing and strength sharpen, and she keeps trying to protect her friends from the appetite she cannot fully explain. Gwi-nam uses his altered state to keep hunting Cheong-san.

Outside the school, the crisis follows On-jo’s father, firefighter Nam So-ju, as he tries to get back to his daughter from a quarantine camp. Detective Song Jae-ik and his companions move through the city while caring for a newborn rescued from an infected mother. Byeong-chan is arrested and tells Jae-ik that the virus changes constantly, making a cure difficult to develop. His account points investigators toward a laptop containing his research, and the military later sends a team to retrieve it. The adults’ efforts do not form a rescue operation. Leaders weigh containment against the survival of people still trapped in Hyosan, while the infection spreads beyond the school. For the students, the wider response brings brief hope, then makes clear how little control they have over the decisions made outside.

The students use sound to draw zombies away from corridors, then push from the music room toward the roof. When soldiers arrive, the students are treated as evacuees and helicopter lifts begin. That plan is cancelled after Eun-ji attacks a student at the quarantine camp: command concludes that its screening cannot reliably separate infected people from carriers who still appear human, and orders the students killed. One soldier refuses to shoot them. The helicopter leaves with Byeong-chan’s laptop, while the students are stranded again. A storm gives them cover to leave the school, and the separate groups reunite as they cross town. So-ju reaches his daughter during another escape. Command then bombs Hyosan to stop the outbreak reaching Seoul. Gwi-nam bites Cheong-san, who draws the infected away from his friends; both disappear in the blast.

The survivors reach a quarantine camp, but rescue does not restore what they have lost. Four months later, martial law is lifted. On-jo visits a memorial for the dead; later, she and her friends return to the ruined school after seeing a fire on its roof. Nam-ra is waiting there, her injuries healing. She tells them that others like her are still alive, then jumps from the roof to join them. The friends watch her leave, knowing she has chosen to live among people who share her changed condition rather than return to the camp. Her departure gives the season’s final meeting a clear cost: the survivors find one another again, but Nam-ra cannot simply resume the life they had before the outbreak.