By 2025, frequent extreme weather and air pollution have rendered Johannesburg no longer suitable for human habitation on the ground. As a result, the residents of Johannesburg established an underground city by expanding old abandoned gold mines for survival. However, the worsening water crisis has made people realize that only by giving back to nature and restoring the ecological environment can they obtain stable and sustainable water resources capable of supporting habitation.

The people of Johannesburg have united to initiate the Plant Cultivation and Water Conservation Project (PCWCP), hoping to improve soil health and restore groundwater levels through technologically enabled plant cultivation. Through the efforts of several generations, the turning point came in 2050 brought on by PCWCP 5.0.