In the caves of Chattooga National Park in the Appalachian Mountains of the United States, Juno (Natalie Jackson Mendoza), Sarah (Shauna Macdonald) and a group of six people experienced the most terrifying moment of their lives. In the end, only Sarah escaped by chance. After that, the police sent a large number of search and rescue personnel into the mountains to search for the bodies of the victims and possible survivors, but in the end they found nothing. Female police officer Rose (Krysten Cummings) was responsible for asking about the whole story of Sarah's disappearance, but Sarah had no memory of what happened in the past. In order to find survivors and the truth, Rose took Sarah to the caves again, and met with search and rescue personnel Casey (Anna Skellern) and Greg (Joshua Dallas). They entered the cave from the abandoned mine entrance and soon found the bodies of Beth and others. The search and rescue personnel realized that this was not a simple disappearance, and at the same time, danger was approaching them quietly...