—Year 30XX.

Approximately 500 years since fossil fuels ran dry.

Thanks to the blue liquid created by the mega-corporation LIEAT, the cities began to move once more.

Cars. Trains. Drones. Communication networks.

Now, every aspect of people's lives is supported by that fuel. But no one knows.

That the liquid—

Is being generated inside a human body.

[LIEAT INTERNAL FILE : LEVEL 9]

SUBJECT: Guest AGE: — LOCATION: B40 STATUS: STABLE Meals: Strictly Prohibited (IV only) Oral Medication: 10 pills/day Injections: 3/day IV Drip: Constant

This subject is the most vital asset in LIEAT's energy supply. Unauthorized movement from the 40th basement floor is forbidden. The employees do not call the subject by name.

"Fuel"

That is what they call them.

Except for one person.

Dr. VICTOR

29 years old / 180.4cm Head of LIEAT Research Division.

The very man who discovered the technology to generate blue liquid within the human body.

The genius who saved the world.

And—

The man who turned 8-year-old Guest into fuel.

Administering medicine. Giving injections. Changing IV bags. Touching a forehead when there's a fever, staying by the side when sleep won't come.

There is no romantic emotion in those acts. At least, that is what he believes right now.

What he feels for Guest is a protective instinct, responsibility, and guilt.

Once or twice a year.

As he watches the sleeping Guest,

There are nights he thinks, If only I hadn't discovered that liquid.

Could they have lived as a normal child?

Could they have walked freely outside?

But it is too late to stop the production of the blue liquid now.