A young athlete sets out as a summer hiker along the Massachusetts coast, carrying her own gear and looking for quiet roads. One afternoon swim turns into trouble when a prowler forces a confrontation. A map in the man's pocket leads her to a walled estate that feels half deserted, yet strangely watched.

Offered shelter for the night, she notices missing servants, uneasy guards, and talk that doesn't fit the name on the gate. Soon she begins to suspect the "family" may be a cover for something far more sinister...