Adolescent David and his teenage sister Lynn are orphaned after their father dies unexpectedly, and are sent to live with their maternal grandparents at their Victorian home in rural California.

En route by bus, the children witness an ominous woman standing in the middle of the road near their grandparents' home, almost causing the driver to get into an accident.

While exploring the surrounding orange orchards with Raymond, David is told that a woman was allegedly murdered inside the tunnel of an irrigation ditch, and that her body was stuffed behind the stone wall.

Fleeing after the explosion, David runs back to his grandparents' home, where he witnesses them burning clothing and dragging a woman's body into the cellar.

David confronts Lynn in the garage, where they find the woman seated in their grandparents' large truck, handcuffed to the steering wheel.

David is shocked to find the woman is still alive, and she explains she is being kept prisoner, and that she came to warn the children about the dangers of living in their grandparents' house.

David fires a shotgun at the front door when a silhouette appears in the window, unintentionally shooting Kenny in the abdomen.

Police arrive moments later, searching for the missing deputy, but cannot find the woman David and Lynn claim have attacked them.

The New York Daily News praised the film as a "clever, low-budget chiller, a twisty, stylishly lensed and well-acted sleeper that supplies more than its share of visceral excitement and authentic suspense.