At the end of the 20th century, a large-scale natural disaster struck the eastern region of a certain country. The disaster wiped out the financial sector and toppled multi-story buildings over a wide area, even affecting the main functions of the capital, resulting in the loss of 158,000 lives.

At the dawn of the 21st century, the PROBE-NEXUS group, commonly known as Probe, began reconstruction efforts in the eastern region of the said country. Probe relocated its own business base to the devastated sector and built a massive city managed by the company.

Rich with colossal funds and cutting-edge technology, the modern Babylon consists of skyscrapers that put old apartment buildings to shame, the largest shopping mall in the world, and recreational facilities that one could mistake for a theme park.

This was the dazzling birth of a symbol for the new century. It became the most essential place on the planet and was christened Zone Prime.