Young woman Michelle (Mary Elizabeth Winstead) had just had an argument with her boyfriend not long ago. She was driving on a dark road at night and suddenly suffered a serious car accident and fell into a coma. When she woke up again, she found herself tied up and locked in a confined space. After a while, a strong and cold man Howard (John Goodman) walked in. Howard, who was a soldier, claimed that the earth had just encountered a terrible biochemical crisis and the people on earth were almost extinct. He built this shelter with complete equipment and resources several years ago just to survive. In the shelter, in addition to Howard and Michelle, there is another young man, Emmett. Michelle was skeptical about Howard's words. She firmly believed that she was detained by a pervert. What is the truth? Threats are everywhere...