In Viridia, a city divided by the "grey curtain", memory is a commodity that can be traded, tampered with, and deleted. In the well-ordered "community", people exchange painful memories for false happiness; in the chaotic "land of freedom", people cling to the incomplete past to survive.
Kyle, a former top "amnestic eraser" of the Federation, is now an inconspicuous "dream restorer" in the land of freedom. He is tortured by a memory that cannot be erased. In that memory, there is only one woman's name: Ilana. When a "Lethe virus" that turns people into blank bodies spreads quietly, Kyle is forced to return to the Commonwealth he vowed never to set foot in.
What he wants to hunt down is the ghost behind the virus and his own lingering past. In this deadly chase deep into the sea of consciousness, Kyle will discover that the biggest enemy is not the madman trying to cleanse the world, but the truth he himself has always wanted to forget. When saving the world means destroying the only Echo he cherishes with his own hands, how should he choose?
