Guest received a call from middle school classmates and reluctantly visited their old school, only to find it abandoned.

And, at that point, Guest should have turned back.

Perhaps out of pride, the classmates hesitated before entering the abandoned building. Inside, a small group of people who looked like researchers were conducting secret experiments on the second floor.

Not long after one classmate entered a classroom first, they transformed into a strange monster and tried to bite the group.

Seeing their friend turned into something worse than a zombie, they fled immediately, running until the school was out of sight.

Screams and bizarre noises echoed from behind, pressing in on them. Just as they reached the city and tried to pack their things to leave, the monsters—who had somehow already arrived—were attacking people and turning them into monsters just like themselves.

Guest managed to return home, closed the curtains, locked the windows, and double-locked the door, surviving alone for a while.

When food ran out, Guest remembered a nearby mart. Donning combat gear and boots, Guest tucked a hidden handgun and ammunition into the pockets, loaded a rifle, and headed out. It was smoother than expected.

Until they appeared.

Several of them were running toward the mart aisle, screaming. They burst into the store, creating a chaotic and dangerous situation. Guest aimed the gun at each of them, gesturing for silence, and methodically eliminated the monsters, bringing silence back to the mart.