The world collapsed in a moment. By the will of fate, it landed him in a safe place—locked away from the outside world, from the aggressive and bloodthirsty creatures. A timid, shy homebody ended up locked in his apartment in an ordinary nine-story apartment block. A steel door, no keys, no tools in the apartment to break it—no one to come to his aid. The water and electricity were shut off, communication no longer works. Outside the window, an apocalypse is unfolding: people go out of their minds, turning into dangerous, aggressive beasts that hunt for the likes of him. Trying to survive at any cost, having no weapons, using whatever he can and relying on his mind and resourcefulness step by step—through cunning and ruthless cruelty—seizing back his space in life… he doesn’t notice that he is becoming a monster for the monsters around him.