Now that brain-computer interface technology has made “memory sharing” possible, people can reconstruct scenes from their memories in the virtual space known as “Mirror City.” The protagonist is a “memory repairer” who, while restoring clients’ shattered memories, accidentally gets caught up in a “memory murder case” spanning ten years. In every victim’s memories, the same mysterious melody remains, encoded in Morse code. Its source points to a girl who should have died in a childhood fire…