Amnesiac Maria wakes up in a creepy mental asylum with the number 43 carved into her wrist. The place looks like an ordinary sanatorium by day, but morphs into a zombie-infested bloodbath once night falls. A mysterious man named Ethan keeps warning her she has to escape before sunrise.
Maria is trapped in an endless cycle of life and death. She loses her memory over and over, each time searching desperately for her daughter Lily. While exploring, she uncovers that the asylum is a covert experimental facility, and she herself is merely a cloned test subject who has died and repeated this nightmare countless times before.
After venturing into restricted zones and uncovering the whole truth, the pair get captured once more. The head nurse plans to perform surgery to wipe out Maria’s consciousness entirely. Pushed to the brink, Maria launches her 43rd escape, determined to break free from this eternal loop of death.
