In a future world composed of floating cities and sea reefs, human memories have become commodities that can be extracted, traded, and even erased. Ling Su, the ace agent of the Department of Order, is a "soul diver" who can sneak into the sea of other people's memories to detect strange cases, but his own past is completely blank.
When a series of unprecedented "consciousness annihilation" cases occur one after another, the victims not only die, but their souls themselves are completely evaporated and turned into an absolute "empty". During the investigation, Ling Su was forced to cooperate with Eva, a memory merchant who wandered in the gray area, and was involved in an urban legend called "Patient Zero".
The clues actually point to his own dusty past and the original sin at the birth of this great technology. When the protection of the system turns into pursuit, and when his former partners draw their swords against each other, Ling Su discovers that the monster he is chasing may be the meaning of his existence.
In this pursuit of memory and identity, he must answer the ultimate question: When your past can be reshaped and your soul can be priced, who are you?
