Jill Parris (Amanda Seyfried) returns home from her night shift to find her sister Molly (Emily Wickersham) kidnapped. Jill escaped from a kidnapper a year ago, and she believes that this criminal is here to catch her again, but he didn't catch her and took Molly away. The police believe that Jill is mentally disturbed since they didn't find any trace of the kidnapper last time Jill reported the case, and are unwilling to use their resources to help her. The police insist that Molly is only temporarily out of contact and should be home soon, and they don't take Jill's report seriously. But Jill knows that Molly may soon encounter an accident. She is so anxious that she can only rely on her own strength. This time she must once again deal with the nightmare she doesn't want to face. However, there are only 12 hours left. Is everything just her abnormal fantasy or is it true? Will she still have time to rescue her dear sister? She decided to pursue the truth alone regardless of the danger. All the answers once again pointed to a mysterious cave in the quiet woods that no one knew about...