In the future city "New Arc City" where neon lights and rain intersect, memory has become a commodity that can be quantified, extracted and traded. While "memory quality" technology heals mental trauma, it also spawns unprecedented criminal forms.
Ling Su is a top "memory quality" detective. He can sneak into the deepest memory palaces of others and pursue the clues left by criminals. He was calm and efficient, like a precise instrument, until he took over a difficult commission - a memory of the genius composer Ye Sheng's composing a world-famous song was mysteriously stolen.
Sneaking into Yesheng's gorgeous memory palace constructed of notes and melodies, Ling Su discovered that the crime scene that should have been perfect had left an "error" mark that shouldn't exist. This mark was like a thorn in his own forgotten past.
