In the floating city of Yun Shangjing shrouded in an energy shield, emotions are regarded as pollution. The third-level purification officer Gu Lin's duty is to remove all "abnormal emotions". When he received the order to eliminate the crimson-level polluter Lin Wan, he found that the surrounding environment of this girl who ran a used bookstore was abnormally clean, and her emotional fluctuations were perfectly sealed in her body. During an in-depth investigation, Gu Lin not only discovered that Lin Wan's medical records were encrypted with level six authority, hiding the shocking secret of "memory transplantation", but also uncovered the darkness beneath the bright surface of the floating city - the city is actually a prison for human beings, and the so-called "emotional purification" is just a lie to cover up the tampering of memories and the selection of experimental subjects. From a loyal enforcer of the system to a rebel who questions the rules, Gu Lin struggles between duty and conscience. Joining hands with Lin Wan, he traveled through underground passages and abandoned facilities, fighting against the Purification Bureau's pursuit and the city's lies, just to uncover the truth about the memory transplant experiment, break through the confinement of the shield, and find the real world outside the barrier. This adventure is not only related to the fate of the two people, but also affects the freedom and future of everyone in the floating city.
