Beyond reality lies the unseen....

A group of explorers, led by Nolan Moore, are drawn to the remote town of Birchlake in Northern California to investigate mysterious stone walls whose presence has never been explained.

Meanwhile a teenage girl has gone missing in the town and before long it becomes clear that the two are connected in terrifying ways.

As the fog thickens, and the darkness closes in, the lines between reality and imagination blur, leaving them questioning their own sanity...