Detective Casey Duncan and her husband, Sheriff Eric Dalton, are entering a new chapter of life as parents to their six-month-old baby. Their family is hidden away in the sanctuary town of Haven's Rock where they can live safe and private lives. But when they encounter hikers too close to the borders of Haven's Rock, they realize they're in danger of being exposed.

When they find one of the hikers dead the next day, they realize that their paranoia was justified, but they're no closer to finding out who these people were and what they were doing in the vicinity of Haven's Rock. Only by tracing the hikers' movements, as well as examining the recent behavior of their closest neighbors, the workers of a secretive mining camp, will they be able to figure out where the threat is coming from and shut it down. Otherwise, the lives of everyone in Haven's Rock--and their safe, secure new existence--are at risk.