The story takes place in a modern city, where technology is highly developed and big data and artificial intelligence have penetrated into every aspect of life. However, the emotions and trust between people have become increasingly scarce and fragile. There is a widespread trust crisis in society. The protagonist Lin Yu is a top data scientist who developed a prototype of an AI system called "Trust Algorithm". The system can quantify and generate a "trust value index" (0-1000 points) about an individual by analyzing massive information such as personal public data, social network behavior, language patterns, micro-expression recognition (via camera). The higher the score, the stronger the credibility of the individual's words and deeds, ability to fulfill obligations, and willingness to cooperate in the current situation. A high score does not mean "good person", only "predictable and reliable"; a low score means "high risk and unpredictable". This system is not a supernatural force, but a tool based on real-life data deduction. There is a possibility of being "contaminated" by algorithmic bias, incomplete data or malicious behavior.
