In Room 203 of Kangyi Nursing Home, at 10 p.m. every night, four elderly residents, averaging 76 years old, return to their twenties or thirties. Eighty-seven-year-old Zhao Lan falls to her death, yet the autopsy report states that all ten of her fingers have no fingerprints. Caregiver Su Nian infiltrates the facility to investigate, only to discover that she is actually the eighth-generation AI created by her grandmother using the memories of a granddaughter who died young. The first seven generations all failed testing. When the facility plans to package and sell the residents' consciousness models to investors, No. 8 Su Nian has just 72 hours left to restore the dignity the four elderly residents deserve after a lifetime.