After surviving a car crash, a young woman wakes up in an underground bunker, where she meets her rescuer, a mysterious man who claims to have saved her from an apocalyptic event. The man insists that the outside world has been rendered uninhabitable, contaminated by a massive chemical attack or some other disaster. The woman is understandably skeptical and terrified, finding herself trapped in a confined space with two men she doesn't know. The bunker is well-stocked and fortified, supposedly to protect them from the dangers that lurk outside.

As time passes, the woman faces the complexities of life in the bunker, including the dynamics between the inhabitants. Her rescuer's intentions and sanity come into question, while the presence of another man in the bunker, a fellow survivor, adds to the tension. She must weigh her desire for freedom against her fear of the unknown terrors that may await outside. The need to escape and find the truth about the outside world grows within her, yet she has to plot her moves carefully, constantly torn between doubt and fear. In this claustrophobic environment, alliances, trust, and the will to survive are tested to their limits.