In an era defined by the unlimited expansion of its metropolises, the world had transformed its face under the weight of excessive urbanization. Where once stood ancestral forests and singing valleys, now sprawling cities stretched out, the confines of which were lost in the blur of an indefinitely extended horizon. Each city, in its vast embrace, had absorbed lands and villages, becoming a dizzying hybrid of concrete and dreams, an endless labyrinth of streets, avenues, and towers climbing toward the heavens as if to defy authority. On this transformed Earth, under a sky often obscured by the incessant ballet of aircraft, there lived an overflowing population, vibrating to the frenetic rhythm of fifteen billion souls. Each individual, a unique spark in this human fireworks display, contributed to the complex and sometimes discordant symphony of collective existence. These fifteen billion hearts beat to the rhythm of machines and thoughts, of hopes woven together in the great carpet of human experience.