Dan Trachtenberg directs this thriller starring Mary Elizabeth Winstead as a young woman who is involved in a car crash. When she comes to, she finds herself a captive in the cellar of a man named Howard (John Goodman), but he assures her he has saved her from the outside world which is no longer safe due to a chemical attack now making it uninhabitable. She begins to question his story, and decides that she must see the outside world for herself.