The time traveler Li Changan, holding a tipless measuring ruler (symbolizing rules and measurement), entered a fantasy world where "rituals and music are broken and rules are distorted". His path is not to reach the pinnacle of immortality, but to become a walking "rule corrector", using the spirit of modern rule of law and management wisdom to eliminate injustice in the world and re-establish the order of the world through romantic and interesting stories.
On the surface, the story is about solving crimes, rectifying, and funny daily routines in the style of a unit drama, but inside it is a continuous speculation on "what is a truly effective order." Li Changan went from measuring the fairness of "one person, one thing" to measuring the "laws of a city and a country", and finally faced the measurement of the "rules of heaven" itself, completing the transformation from "rule-holder" to "legislator".
