Mike Yarnell is a burnt out cop, who is being investigated by internal affairs. When he begins taking out his frustration on his wife, she turns to the man handling her husband's case for protection. However, there's more to her than what meets the eye.

Fleeing her past, a troubled hiker and her dog traverse the Appalachian Trail, only to fall under the spell of a dangerous man. As obsession and visions mount, she's drawn toward Mile 666, where lust, death, and something ancient await.