AD 2254, New Chang'an City. Here, your joys, sorrows, sorrows and joys can be packaged into crystals and placed on the shelves with clearly marked prices.
Ling Xiao, a promising agent of the "Emotional Stability Bureau", was blown up by a "Happy Bomb" in an accident and became a private detective unable to understand humor. He can accurately analyze the logical structure of a joke, but he can't feel the slightest happiness.
When the city's greatest comedy king "Clown J" was drained of his life's "humor" and "inspiration" and turned into a living sculpture that couldn't laugh, Ling Xiao took on the most unsuitable case for him.
Jealous rivals, mysterious agents, ardent fans... Everyone has a suspect. In order to find out the truth, Ling Xiao plunged into the urban black market composed of lies, desires and cheap synthetic happiness. He must use his unwavering logic to fight against the "emotional weapons" that can trigger collective madness, and to deconstruct a "last joke" that can subvert the entire world.
In this era where you have to pay to even smile, how will a detective who can't smile find the stolen happiness and his own long-lost truth?
