Leanne, a teenage girl wakes up in a small, dim room with no memories. The only clue is the word Theresia scribbled upon a piece of paper. The first areas of the game instruct the player on the controls, set the atmosphere and introduce the survival aspect. The building is not only the sub-basement of a larger complex, but also riddled with hidden traps. Most doors are locked, barricaded, or blocked by environmental hazards. Leanne discovers she is in an underground prison facility, which stretches over several underground stories and includes waterworks, storage and torture rooms, and unknown crypts. In the upper levels, more of the setting and Leanne's background are revealed: the country is losing the war, and the prison is part of a military installation which includes a testing laboratory, run by a woman named Maylee, who Leanne has seen in flashbacks. She also has flashbacks of a young man named Sacha and a silver-haired woman drenched in blood.

Leanne, a teenage girl wakes up in a small, dim room with no memories. The only clue is the word Theresia scribbled upon a piece of paper. The first areas of the game instruct the player on the controls, set the atmosphere and introduce the survival aspect. The building is not only the sub-basement of a larger complex, but also riddled with hidden traps. Most doors are locked, barricaded, or blocked by environmental hazards. Leanne discovers she is in an underground prison facility, which stretches over several underground stories and includes waterworks, storage and torture rooms, and unknown crypts. In the upper levels, more of the setting and Leanne's background are revealed: the country is losing the war, and the prison is part of a military installation which includes a testing laboratory, run by a woman named Maylee, who Leanne has seen in flashbacks. She also has flashbacks of a young man named Sacha and a silver-haired woman drenched in blood.