When a college student vanishes near the mysterious lights of Brown Mountain, folklore professor Adrian Cross receives a cryptic photograph taken moments before the disappearance-an image that appears to capture the legendary lights behaving with impossible intelligence. Drawn to the mountain, Adrian begins investigating a phenomenon long dismissed as folklore. He is joined by Marissa Vega, a sociology professor determined to uncover whether the mystery hides a human conspiracy, and Henry Caldwell, a history professor whose knowledge of regional legends reveals that the lights have been appearing-and people disappearing-for centuries. As the trio uncovers forgotten journals, buried incidents, and warnings hidden in local stories, they realize the Brown Mountain Lights may not be a natural mystery at all. Something ancient may be watching from the mountain's fog. And those who seek the truth may become part of the legend themselves.