New graduate Lin Xiaobei becomes a sanitation worker after failing to find a job. One stormy night, he rescues a mysterious black cat and unexpectedly awakens the “City Light System.” For every ton of garbage he cleans up, he can exchange it for money and skills. By day, he sweeps the streets; by night, he becomes the “Trash Hunter,” gradually exposing the truth behind the city’s pollution, from a chemical plant’s secret discharge of waste to a crisis at a landfill.
Facing a manhunt ordered by chemical plant owner Zhao Tianxiong and a technological onslaught from the multinational conglomerate EcoCorp, Lin Xiaobei forms the “Night Shift Sanitation Squad.” Together with homeless people, retired workers, and other laborers from the bottom of society, they use the System’s skills to purify water sources and transform mountains of garbage. They even turn the Pacific garbage patch into an ecological oasis. After a villainous scientist defects and sacrifices himself, the team finally crushes the conglomerate’s “Human Elimination Plan” and drives the passage of the global “Waste Code.”
Just as the System runs out of energy, Lin Xiaobei discovers that it is actually an experiment conducted by an alien civilization, the “Universal Cleaning Alliance.” Earth has been designated an “observation subject” because of its severe pollution. He proves humanity’s worth with garbage-recycling technology, refuses to become a savior, and returns to his job as a street cleaner. One stormy night, he hands his broom to an apprentice who has awakened new skills. In the final scene, an alien ship streaks across the night sky, leaving the suspense of a hundred-year observation period.
Very sci-fi, like the reappearance of "The Three-Body Problem"
So wonderful!