In 2016, a group of filmmakers disappeared in the mountains of East Tennessee. Three years later their footage was found.

While filming a documentary series about Appalachian folklore and mythology, a crew of amateur filmmakers uncover the legend of a mysterious box hidden away deep in a wilderness area known as "Jeffrey's Hell" in the Appalachian mountains of East Tennessee. As the mystery unfolds they soon discover that some secrets are best locked away and forgotten. Based on actual events.