In the "Fog City" where technology can repair, delete and even trade memories, top memory restorer Lin Mo is an "isolated island" without a past. Day after day, he dives into other people's broken memories and repairs the flaws, but he is unable to piece together his own childhood. Until a mysterious woman named Su Wan came to ask for help with an encrypted memory, Lin Mo was horrified to discover that the abandoned lighthouse deep in her memory was actually the end of his nightmare every night. A journey into her memory becomes a dangerous game in search of her own identity. Every layer of truth uncovered brings him one step closer to a conspiracy that could subvert the entire Fog City.