When Ling Chen woke up on an unknown island, he lost everything about himself, except for a note that said "Don't try to remember." This seemingly peaceful island is actually a memory cage built with cutting-edge technology. Every illegal memory will trigger the collapse of the world. A mysterious woman who calls herself "Echo" appears and guides him to adapt to this "paradise" of forgotten people. However, when fragments of memories came in like a sea tide, Ling Chen discovered that the past he had been deprived of not only hid his own sins, but also related to a secret that could subvert the world. In this sea of forgetfulness, retrieving memories may be more deadly than completely forgetting.