Jin-woo's schizophrenia was no secret—his daily antipsychotic medication and that unfortunate incident saw to that. Starting high school with everyone knowing about his condition meant the bullies came without hesitation. He wanted only to survive unnoticed, to avoid becoming a target. Instead, he ended up in the same class as his tormentors and an annoying popular girl obsessed with calling him her childhood friend. His careful plans for invisibility shattered when a zombie virus erupted, sealing the school and everyone inside. Jin-woo discovers a terrifying truth: he can see the undead when others can't. Worse, he's somehow connected to the outbreak itself. Trapped in a high school turned survival nightmare, surrounded by his bullies and that persistent girl, with infected hordes closing in outside, Jin-woo faces an impossible decision. Does he endure the social apocalypse within the building, or risk the walking dead beyond its walls?