In Xinhai City, Lin Mo, the top "memory cleaner", peels away painful memories for clients with scalpel-like precision. He is calm, self-disciplined, and firmly believes that forgetting is the best salvation, but he is powerless to deal with the blankness of his childhood. When a mysterious woman Su Wan appeared in front of him with a bizarre request - to forget a supposedly warm lullaby - Lin Mo's perfect world began to collapse. That melody was like a key, accidentally opening the door to his own dusty memory. He discovers that behind the technology he relies on for a living lies a huge lie about identity, love and betrayal. He is not a memory cleaner, perhaps, he is just a carefully shaped prisoner.
