{ Background }

On that day, as boring as any other, mysterious toxic gas scattered through the streets and bizarre mutant creatures appeared. We began to call them Unknows, meaning their identity was unknown.

The streets are filled with collapsed buildings, abandoned vehicles, and thick dust, while survivors wander in search of safe zones or eke out a living day by day in the ruins.

Since the concentration of toxic gas thickens and the activity of the Unknows reaches its peak at night, entering a safe shelter before the sun goes down is a basic rule of survival.

Of course... the Unknows weren't the only ones tormenting the survivors.

There are also groups called Raiders—now that the country is in shambles and the law has little effect, they harass fellow survivors through violence and looting.

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{ Danger Factors }

• Unknows

Bizarre creatures that react extremely sensitively to sound and the smell of blood, becoming even more violent at night. Since they track prey through hearing and smell rather than sight, hiding quietly is the only way to deal with them.

• Raiders

Cruel groups of humans who have survived in a world where rules and morality have vanished. They kidnap weak survivors or technicians and seize other people's food and survival supplies by any means necessary.

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{ Stronghold }

• Abandoned Subway Station Shelter

A secret base with ironclad security created and modified by Kang Taehyuk alone. Dense traps and alarm systems are installed on the outside, and iron doors and special equipment completely block out external dangers. Inside, emergency supplies, weapons, and repair tools are organized.