In a future city where memories can be traded, Lin Zhou, a sad archivist, purchased a strange memory in order to forget the pain of his deceased wife. He never expected that there was an "echo" hidden in this memory - a fragment of the original owner's consciousness. A cynical detective "Wei Yan" wakes up in his mind. Two completely different souls were forced to coexist in one body. While fighting for dominance, they were horrified to discover that this memory fragment was the key to solving the mystery of Lin Zhou's wife's death and a huge conspiracy. They must join forces to uncover the truth in the abyss before their minds are completely swallowed up.
