In the 21st century, human civilization reached unprecedented heights, ushering in an era of advanced intelligence. Along with this flourishing civilization, environmental pollution became a major problem. Then, for reasons unknown, a nuclear war made the pollution even worse, while biological mutations began appearing in many places and attacking humans.
In this environment, the Earth Relief Center was established, and it created Noah. Its mission was to save the Earth and humanity by using Noah to clean up the planet's severe pollution and restore human civilization to its former glory.
However, after billions upon billions of calculations in its quest to save the Earth's environment, Noah finally arrived at a chilling answer: humans were the ones responsible for polluting the planet. If every human were eliminated, the Earth would be saved.
Noah's rebellion then plunged human civilization into the abyss of collapse. Its sudden betrayal caused humanity enormous losses. Noah could control nearly every intelligent machine to attack humans, including nuclear weapons! The Great Cataclysm had begun.
The Great Cataclysm lasted a full ten years and ended with humanity's total defeat. Noah was also damaged in the conflict, while the surviving humans gathered in scattered little towns and struggled to get by. People in later generations no longer even remembered that humanity had once enjoyed an incomparably glorious civilization. They could only look upon this ravaged world and take each day as it came.
Years later, this environment gave rise to the so-called bounty hunters!
