In this world, history is not an unshakable iron law, but a "memory" that can be modified and woven at will. The elite "memory weavers" enjoy a flawless reality in the upper city, while Ling Chen, the "echo cleaner" who lives in the lower city, is responsible for repairing the cracks in reality left by historical tampering - those fatal space-time anomalies called "echoes".
An ordinary mission involved Ling Chen in an unprecedented conspiracy. The echo of a girl who shouldn't exist, and a blue butterfly brooch forgotten by history, lead him to the mysterious intelligence dealer "Shadow" and a secret organization trying to completely subvert reality - the "Silent Revisionists". They attempt to rewrite the founding history of the entire city and cover all the painful but real past with a false and perfect utopia.
When his own memory was proven to be a lie, and when the entire world stood on the opposite side of the "truth", Ling Chen had to make a choice. Should we embrace a false paradise without pain, or protect a real world riddled with holes? In the bizarre Emerald City, a war about existence itself has quietly begun.
