In 2097, the Earth's environment continues to deteriorate to a zero point. At the same time, a "doomsday virus" emerged on Earth. Those infected by the virus either die or mutate. As a result, the Earth's federal government was formed and the last of its resources were used to build a number of scattered ships to colonise satellites in Earth orbit over the next 500 years. They were going to move the surviving healthy elite into space in small groups to get away from the virus and contamination and create an isolated world. But the rest of the human race, forced to remain on Earth, struggled to survive in the face of disease and famine, and they gradually began to degenerate. The lack of supplies and systematic education and the slow loss of science and technology forced them to return to the agrarian age and gradually forget their history. The few remaining fragments of history in their minds became myths. ...... These genetically flawed remnants of the Earth were later called "mortals" by the elite in space.

Meanwhile, the elite humans in space did not give up. They continued to research a vaccine against the virus and continued to capture the degenerate humans on Earth for experimentation. As this went on for centuries, a division began to form within the upper echelons of the elite human race. One group advocated the elimination of all infected remnants on Earth and the return to Earth, no longer wandering in space. As a result, they spontaneously formed a faction, the "Returners". They eventually evolved into the Earth Rebels, who are constantly active between space and Earth. With the ultimate goal of wiping out the Earth's remnants, they continue to create fratricidal events and disasters on Earth, even spreading viruses to kill the remnants. They want to exterminate the descendants of infected humans and return to Earth to create a new world.

Another group, known as the "rebirthists", advocated continuing to develop a cure for the virus and then coexisting with the remnants of Earth. They also traveled back and forth between space and Earth in search of a cure for the virus. They have built space lifts in different parts of the planet to connect Earth to space stations and to transport vital supplies. They have also set up observatories on the sea, on mountain tops, underground and in the stratosphere to study the mortals in areas that are out of their reach in order to find a way to combat the virus. At the same time they had to stop the Returners from killing and persecuting the Remnants of Earth, and help them relearn the system, unite the survivors and build towns.

In 2597 AD, a lab leak caused some of the Earth infected to escape the lab, and then the virus began to spread rapidly in space as well. Eventually a civil war breaks out ...... The few elite survivors are left to gather the limited resources in the wreckage of space to survive, but they have to face the mutated monsters inside the wreckage and the competition for resources between the different forces ......

Until a special soldier awakens in deep space, armed with the Federation's secret weapon that may change the fate of humanity's future ......