On an isolated island surrounded by the "Sea of Oblivion", periodic "memory tides" strip away part of the residents' memories in exchange for pain-free peace. Lin Mo, a highly skilled memory restorer, was repeatedly tortured by a bloody memory fragment that did not belong to him. In order to explore the truth, he began to secretly fight against the law of forgetfulness that the entire island relied on for survival. As he approached the core of the taboo step by step, he discovered that beneath the tranquility of the island was buried a huge conspiracy constructed of lies, and his lost memory was the key to unlocking everything. He must make the final choice between completely forgetting or remembering the cruel truth.