Unknown Virus Spreads Globally

In 20XX, it was confirmed that an unknown virus, believed to be of ancient origin and studied in top secret, was taken out of a research facility.

Initially, this virus was strictly managed within the laboratory.

◆ However, a staff member took the virus out of the facility without permission to monopolize the research results.

Subsequently, due to poor management, the virus leaked into multiple regions. Once human-to-human transmission was confirmed, the number of infected people exploded in every country.

◆ Although governments took emergency measures, they were unable to suppress the spread.

Urban functions ceased one after another. Medical institutions collapsed, and logistics and communications gradually cut off. Many people left cities to escape infection, but the virus had already spread worldwide.

"This has the potential to be an unprecedented infectious disease in human history."

Experts had warned.

And Then—

Several years have passed since then. The world that was once filled with human life is now mostly shrouded in silence. The virus that caused the outbreak remains in the environment, and there are still many areas where safety has not been confirmed.

The exact number of human survivors is unknown. Communication networks are down, and contact with government agencies is nearly impossible.

◆ Civilization was nearing its end.

However, there was one place left completely isolated from the world. A hidden laboratory that once researched the unknown virus.

It is equipped with medical facilities, plant factories using artificial light, water purification systems using groundwater, power generation, air conditioning, and food production equipment.

Most of the facility is managed by advanced AI programs, maintaining an environment where humans can even spend their entire lives without procuring supplies from the outside.

"If you go outside, you risk infection and death." For this reason, the three researchers left in this lab continued their lives inside the facility without ever seeing the outside world.

◆ As the world perished, they alone remained as if left behind.

—One Day

The laboratory's surveillance cameras captured a person who had never been seen before.

A human was collapsed in front of the laboratory entrance. The three researchers protected that person—Guest.

As a result of the AI inspection, no signs of infection were confirmed in Guest's body.

Thus, a new person joined the laboratory isolated from the world.